<HTML>
<HEAD>
<TITLE>sv8</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
<!-- PAGEBREAK -->
<DIV style="font-family: 'Times New Roman',Times,serif">


<DIV align="center" style="font-size: 10pt; margin-top: 18pt">As filed with the Securities and Exchange Commission on June&nbsp;4, 2010
</DIV>


<DIV align="right" style="font-size: 10pt; margin-top: 3pt">Registration Statement No.&nbsp;333-
</DIV>


<DIV style="width: 100%; border-bottom: 2pt solid black; font-size: 1pt">&nbsp;</DIV>
<DIV style="width: 100%; border-bottom: 1pt solid black; font-size: 1pt">&nbsp;</DIV>




<DIV align="center" style="font-size: 14pt; margin-top: 12pt"><B>UNITED STATES<BR>
SECURITIES AND EXCHANGE COMMISSION</B>
</DIV>

<DIV align="center" style="font-size: 12pt"><B>WASHINGTON, DC 20549</B>
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 12pt"><DIV align="center"><DIV style="FONT-size: 3pt; margin-top: 16pt; width: 26%; border-top: 1px solid #000000">&nbsp;</DIV></DIV></DIV>

<DIV align="center" style="font-size: 18pt; margin-top: 12pt"><B>FORM S-8</B>
</DIV>


<DIV align="center" style="font-size: 12pt; margin-top: 12pt"><B>REGISTRATION STATEMENT<BR>
UNDER THE SECURITIES ACT OF 1933</B>
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 12pt"><DIV align="center"><DIV style="FONT-size: 3pt; margin-top: 16pt; width: 26%; border-top: 1px solid #000000">&nbsp;</DIV></DIV></DIV>

<DIV align="center" style="font-size: 24pt; margin-top: 12pt"><B>ATMI, INC.</B>
</DIV>

<DIV align="center" style="font-size: 10pt">(Exact name of registrant as specified in its charter)</DIV>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="47%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="47%">&nbsp;</TD>
</TR>
<TR></TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD align="center" valign="top"><B>Delaware</B><BR>
(State or other jurisdiction of <BR>
incorporation or organization)
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top"><B>06-1481060</B><BR>
(IRS Employer<BR>
Identification No.)</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 12pt"><B>7 Commerce Drive<BR>
Danbury, Connecticut 06810</B><BR>
(Address of Principal Executive Offices)</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 12pt"><B>ATMI, Inc. 2010 Stock Plan</B><BR>
(Full Title of the Plan)</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 12pt"><B>Ellen T. Harmon, Esq.<BR>
Executive Vice President and Chief Legal Officer<BR>
ATMI, Inc.<BR>
7 Commerce Drive<BR>
Danbury, Connecticut 06810<BR>
(203)&nbsp;794-1100</B></DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 12pt">(Name, Address and Telephone Number, including area code, of Agent for Service)</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 12pt">Copies
of all communications, including all communications sent to agent for service should be sent to:</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 12pt"><B>Michael Grundei, Esq.<BR>
Wiggin and Dana LLP<BR>
400 Atlantic Street<BR>
Stamford, Connecticut 06901<BR>
(203)&nbsp;363-7600</B></DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Indicate by check mark whether the registrant is a large accelerated filer, an accelerated
filer, a non-accelerated filer, or a smaller reporting company. See the definitions of &#147;large
accelerated filer,&#148; &#147;accelerated filer&#148; and &#147;smaller reporting company&#148; in Rule&nbsp;12b-2 of the
Exchange Act.<br>
(Check one):
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="22%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="22%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="22%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="22%">&nbsp;</TD>
</TR>
<TR></TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD align="center" valign="top"><FONT style="white-space: nowrap">Large accelerated filer <FONT style="font-family: Wingdings">&#111;</FONT></FONT>
</TD>
    <TD>&nbsp;</TD>

<TD align="center" valign="top"><FONT style="white-space: nowrap">Accelerated
filer <FONT style="font-family: Wingdings">&#254;</FONT></FONT>
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top"><FONT style="white-space: nowrap">Non-accelerated filer <FONT style="font-family: Wingdings">&#111;</FONT></FONT>
<FONT style="white-space: nowrap">(Do not check if a smaller reporting company)</FONT>
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top"><FONT style="white-space: nowrap">Smaller reporting company <FONT style="font-family: Wingdings">&#111;</FONT></FONT></TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>CALCULATION OF REGISTRATION FEE</B>
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="1%">&nbsp;</TD>
    <TD width="29%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD><!-- VRule -->
    <TD width="1%">&nbsp;</TD>
    <TD width="21%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD><!-- VRule -->
    <TD width="1%">&nbsp;</TD>
    <TD width="8%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD><!-- VRule -->
    <TD width="1%">&nbsp;</TD>
    <TD width="20%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD><!-- VRule -->
    <TD width="1%">&nbsp;</TD>
    <TD width="12%">&nbsp;</TD>

    <TD width="1%">&nbsp;</TD>
</TR><TR style="font-size: 1px" valign="bottom">
    <TD nowrap align="left" colspan="15" style="border-bottom: 3px double #000000">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">    <TD width="1%">&nbsp;</TD>

    <TD>&nbsp;</TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Proposed Maximum</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Proposed Maximum</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">    <TD width="1%">&nbsp;</TD>

    <TD nowrap align="center"><B>Title of Securities</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Amount to be</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Offering</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Aggregate Offering</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Amount of</B></TD>
    <TD width="1%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">    <TD width="1%">&nbsp;</TD>

    <TD nowrap align="center" style="border-bottom: 0px solid #000000"><B>to be Registered</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" style="border-bottom: 0px solid #000000"><B>Registered(1)</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Price Per Share(2)</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Price</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" style="border-bottom: 0px solid #000000"><B>Registration Fee</B></TD>
    <TD width="1%">&nbsp;</TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD width="1%" style="border-top: 2px solid #000000">&nbsp;</TD>
                    <TD style="border-top: 2px solid #000000" nowrap><DIV style="margin-left:15px; text-indent:-15px"><B>Common Stock, $.01
par value
per share</B></DIV></TD>
    <TD style="border-right: 2px solid #000000; border-top: 2px solid #000000">&nbsp;</TD>
    <TD style="border-top: 2px solid #000000">&nbsp;</TD>
    <TD align="center" valign="bottom" style="border-top: 2px solid #000000"><B>3,000,000 shares</B></TD>
    <TD style="border-right: 2px solid #000000; border-top: 2px solid #000000">&nbsp;</TD>
    <TD style="border-top: 2px solid #000000">&nbsp;</TD>
    <TD align="center" valign="bottom" style="border-top: 2px solid #000000"><B>$15.785</B></TD>
    <TD style="border-right: 2px solid #000000; border-top: 2px solid #000000">&nbsp;</TD>
    <TD style="border-top: 2px solid #000000">&nbsp;</TD>
    <TD align="center" valign="bottom" style="border-top: 2px solid #000000"><B>$47,355,000.00</B></TD>
    <TD style="border-right: 2px solid #000000; border-top: 2px solid #000000">&nbsp;</TD>
    <TD style="border-top: 2px solid #000000">&nbsp;</TD>
    <TD align="center" valign="bottom" style="border-top: 2px solid #000000"><B>$3,376.41</B></TD>
    <TD width="1%" style="border-top: 2px solid #000000">&nbsp;</TD>
</TR>
<TR style="font-size: 1px" valign="bottom">
    <TD nowrap align="left" colspan="15" style="border-top: 3px double #000000">&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 3pt; width: 18%; border-top: 0px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="3%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left">(1)</TD>
    <TD>&nbsp;</TD>
    <TD>Plus such additional indeterminable number of shares as may be required pursuant to the ATMI,
Inc. 2010 Stock Plan in the event of a stock dividend, stock split, recapitalization or other
similar change in the Common Stock.</TD>
</TR>

<TR style="font-size: 3pt"><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD nowrap align="left">(2)</TD>
    <TD>&nbsp;</TD>
    <TD>Computed in accordance with Rules 457(c) and 457(h) under the Securities Act of 1933, as
amended, such computation is based on $15.785 per share (the average of the high and low prices as
reported on the NASDAQ Global Select Market on June&nbsp;1, 2010).</TD>
</TR>

</TABLE>



<DIV style="width: 100%; border-bottom: 1pt solid black; margin-top: 10pt; font-size: 1pt">&nbsp;</DIV>
<DIV style="width: 100%; border-bottom: 2pt solid black; font-size: 1pt">&nbsp;</DIV>













<P align="center" style="font-size: 10pt"><!-- Folio -->&nbsp;<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">












<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>PART II</B>
</DIV>


<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>INFORMATION REQUIRED IN THE REGISTRATION STATEMENT</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;3. Incorporation of Documents by Reference.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">There are hereby incorporated by reference in this Registration Statement of ATMI, Inc. (the
&#147;Company&#148;) the following documents and information heretofore filed under the Securities Exchange
Act of 1934, as amended (the &#147;Exchange Act&#148;) with the Securities and Exchange Commission:
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(a)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>The Company&#146;s Annual Report on Form 10-K for the fiscal year ended December&nbsp;31,
2009;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(b)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>The Company&#146;s Quarterly Report on Form 10-Q for the quarter ended March&nbsp;31, 2010;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(c)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>The Company&#146;s Current Reports on Form 8-K filed with the Securities and Exchange
Commission on April&nbsp;9, 2010 and May&nbsp;26, 2010;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(d)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>The Company&#146;s Proxy Statement filed with the Securities and Exchange Commission on
April&nbsp;9, 2010;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" style="background: transparent">&nbsp;</TD>
    <TD width="2%" nowrap align="left">(e)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>The description of the common stock of the Company&#146;s predecessor, Advanced
Technology Materials, Inc. (&#147;ATM&#148;), as set forth in ATM&#146;s Registration Statement on Form
8-A, filed on November&nbsp;1, 1993, which description was amended on Form 8-A/A on November
11, 1993, and any amendment or report filed for the purpose of further updating such
description.</TD>
</TR>

</TABLE>
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">All documents filed by the Company pursuant to Sections&nbsp;13(a), 13(c), 14 and 15(d) of the Exchange
Act after the date of this Registration Statement and prior to the filing of a post-effective
amendment which indicates that all securities offered have been sold or which deregisters all
securities then remaining unsold, shall be deemed to be incorporated by reference in this
Registration Statement and to be part hereof from the date of filing such documents.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">The Company will provide, without charge to each person, including any beneficial owner, to whom
this document is delivered, upon written or oral request of such person, a copy of any or all of
the documents incorporated herein by reference (other than exhibits, unless such exhibits
specifically are incorporated by reference into such documents or this document). Requests for such
documents submitted in writing, should be addressed to the office of the corporate Secretary, ATMI,
Inc., 7 Commerce Drive, Danbury, Connecticut 06810. Oral requests should be made by telephone to
the corporate Secretary at (203)&nbsp;794-1100.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;4. Description of Securities.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Not applicable.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;5. Interests of Named Experts and Counsel.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Not applicable.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;6. Indemnification of Directors and Officers.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Section&nbsp;145 of the General Corporation Law of the State of Delaware (&#147;Delaware Law&#148;) empowers a
Delaware corporation to indemnify any persons who are, or are threatened to be made, parties to any
pending or completed action, suit or proceeding, whether civil, criminal, administrative or
investigative (other than an action by or in the right of such corporation), by reason of the fact
that such person is or was a director,
</DIV>



<P align="center" style="font-size: 10pt"><!-- Folio -->&nbsp;<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">



<DIV align="left" style="font-size: 10pt; margin-top: 6pt">officer, employee or agent of such corporation, or is or was serving at the request of such
corporation as a director, officer, employee or agent of another corporation or enterprise. The
indemnity may include expenses (including attorneys&#146; fees), judgments, fines and amounts paid in
settlement actually and reasonably incurred by such person in connection with such action, suit or
proceeding, provided that such person acted in good faith and in a manner he or she reasonably
believed to be in or not opposed to the corporation&#146;s best interests, and, for criminal actions or
proceedings, had no reasonable cause to believe his or her conduct was unlawful. A Delaware
corporation may indemnify officers and directors against expenses (including attorney&#146;s fees) in
connection with the defense or settlement of an action by or in the right of the corporation under
the same conditions, except that no indemnification is permitted without judicial approval if the
officer or director is adjudged to be liable to the corporation. Where an officer or director is
successful on the merits or otherwise in the defense of any action referred to above, the
corporation must indemnify him or her against the expenses which such officer or director actually
and reasonably incurred.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">The Company&#146;s Restated Certificate of Incorporation (the &#147;Charter&#148;) provides for the
indemnification of each director of the Company to the fullest extent permitted by Delaware Law.
The Charter also provides that, to the fullest extent permitted by Delaware Law, no director of the
Company shall be liable to the Company or any of its shareholders for monetary damages for breach
of fiduciary duty as a director. The Company&#146;s Amended and Restated Bylaws provide further that
the Company shall indemnify any director or officer who was or is a party to or is involved in, or
is threatened to be made a party to or involved in, any third party proceeding by reason of the
fact that such person was or is a director or an officer, against expenses, judgments, fines and
amounts paid in settlement actually and reasonably incurred by such person in connection with
investigating, defending, settling, being a witness in, or participating in (including on appeal),
or preparing for any of the foregoing, if such person acted in good faith and in a manner such
person reasonably believed to be in or not opposed to the best interests of the Company and, with
respect to any criminal third party proceeding, had no reasonable cause to believe such conduct was
unlawful. In addition, the Amended and Restated Bylaws provide that the Company shall indemnify
any director or officer who was or is a party to or is involved in, or is threatened to be made a
party to or involved in, any corporate proceeding by reason of the fact that such person was or is
a director or officer of the Company, against expenses actually and reasonably incurred by such
person in connection with investigating, defending, settling, being a witness in, or participating
in (including on appeal) such corporate proceeding, or preparing for any of the foregoing, if such
person acted in good faith and in a manner such person reasonably believed to be in or not opposed
to the best interests of the Company; provided, however, that no indemnification shall be made in
respect of any claim, issue or matter as to which such person shall have been adjudged to be liable
to the Company except and only to the extent that the Court of Chancery of the State of Delaware or
the court in which such corporate proceeding was brought shall determine upon application that,
despite the adjudication of liability, but in view of all the circumstances of the case, such
person is fairly and reasonably entitled to indemnity for such expenses which the Court of Chancery
of the State of Delaware or such other court shall deem proper.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Section&nbsp;145 of Delaware Law also empowers corporations to purchase and maintain insurance on behalf
of any person who is or was an officer or director of the corporation whether or not the
corporation would have the power to indemnify such officer or director against such liability under
the provisions of Section&nbsp;145. The Company has purchased and maintains a directors&#146; and officers&#146;
liability policy for such purposes.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;7. Exemption From Registration Claimed.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Not applicable.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;8. Exhibits.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">4.1 Restated Certificate of Incorporation (1)
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">4.2 Amended and Restated Bylaws (2)
</DIV>




<P align="center" style="font-size: 10pt"><!-- Folio -->2<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">



<DIV align="left" style="font-size: 10pt; margin-top: 6pt">4.3 Rights Agreement, dated as of October&nbsp;13, 2000, between ATMI, Inc. and Fleet National Bank,
as Rights Agent (3)
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">4.4 ATMI,
Inc. 2010 Stock Plan (filed herewith)
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">5.1 Opinion of Wiggin and Dana LLP (filed herewith)
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">23.1
Consent of Independent Registered Public Accounting Firm (filed herewith)
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">23.2 Consent of Counsel (included in Exhibit&nbsp;5.1)
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">24.1 Power of Attorney (included in signature page)
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="3%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left">(1)</TD>
    <TD>&nbsp;</TD>
    <TD>Incorporated by reference to Exhibit 3(i) to the Company&#146;s Current Report on Form 8-K filed
with the Securities and Exchange Commission on August&nbsp;3, 2005.</TD>
</TR>

<TR style="font-size: 3pt"><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD nowrap align="left">(2)</TD>
    <TD>&nbsp;</TD>
    <TD>Incorporated by reference to Exhibit&nbsp;3.1 to the Company&#146;s Current Report on Form 8-K filed with
the Securities and Exchange Commission on December&nbsp;18, 2008.</TD>
</TR>

<TR style="font-size: 3pt"><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD nowrap align="left">(3)</TD>
    <TD>&nbsp;</TD>
    <TD>Incorporated by reference to Exhibit&nbsp;4.02 to the
Company&#146;s Annual Report on Form 10-K filed with
the Securities and Exchange Commission on February&nbsp;20, 2009.</TD>
</TR>

</TABLE>



<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;9. Undertakings.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(a)&nbsp;The undersigned registrant hereby undertakes:
</DIV>



<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">(1)&nbsp;To file, during any period in which offers or sales are being made, a post-effective
amendment to this registration statement:
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i) To include any prospectus required by Section&nbsp;10(a)(3) of the Securities Act of 1933,
as amended (the &#147;Securities Act&#148;);
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii) To reflect in the prospectus any facts or events arising after the effective date of
the registration statement (or the most recent post-effective amendment thereof) which,
individually or in the aggregate, represent a fundamental change in the information set forth
in the registration statement. Notwithstanding the foregoing, any increase or decrease in
volume of securities offered (if the total dollar value of securities offered would not exceed
that which was registered) and any deviation from the low or high end of the estimated maximum
offering range may be reflected in the form of prospectus filed with the Commission pursuant
to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a
20&nbsp;percent change in the maximum aggregate offering price set forth in the &#147;Calculation of
Registration Fee&#148; table in the effective registration statement.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(iii) To include any material information with respect to the plan of distribution not
previously disclosed in the registration statement or any material change to such information
in the registration statement;
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<I>Provided, however</I>, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the information
required to be included in a post-effective amendment by those paragraphs is contained in
reports filed with or furnished to the Commission by the registrant pursuant to Section&nbsp;13 or
Section 15(d) of the Securities Exchange Act of 1934, as amended (the &#147;Exchange Act&#148;) that are
incorporated by reference in the registration statement.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2) That, for the purpose of determining any liability under the Securities Act, each such
post-effective amendment shall be deemed to be a new registration statement relating to the
securities offered herein, and the offering of such securities at that time shall be deemed to
be the initial bona fide offering thereof.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(3) To remove from registration by means of a post-effective amendment any of the securities
being registered which remain unsold at the termination of the offering.
</DIV>

<P align="center" style="font-size: 10pt"><!-- Folio -->3<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 2%">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(4) That, for the purpose of determining liability of the registrant under the Securities Act
to any purchaser in the initial distribution of the securities, the undersigned registrant
undertakes that in a primary offering of securities of the undersigned registrant pursuant to
this registration statement, regardless of the underwriting method used to sell the securities
to the purchaser, if the securities are offered or sold to such purchaser by means of any of
the following communications, the undersigned registrant will be a seller to the purchaser and
will be considered to offer or sell such securities to such purchaser: (i)&nbsp;any preliminary
prospectus or prospectus of the undersigned registrant relating to the offering required to be
filed pursuant to Rule&nbsp;424; (ii)&nbsp;any free writing prospectus relating to the offering prepared
by or on behalf of the undersigned registrant or used or referred to by the undersigned
registrant; (iii)&nbsp;the portion of any other free writing prospectus relating to the offering
containing material information about the undersigned registrant or its securities provided by
or on behalf of the undersigned registrant; and (iv)&nbsp;any other communication that is an offer
in the offering made by the undersigned registrant to the purchaser.
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(b)&nbsp;The undersigned registrant hereby undertakes that, for purposes of determining any liability
under the Securities Act, each filing of the registrant&#146;s annual report pursuant to Section 13(a)
or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit
plan&#146;s annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by
reference in the Registration Statement shall be deemed to be a new registration statement relating
to the securities offered herein, and the offering of such securities at that time shall be deemed
to be the initial bona fide offering thereof.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(c)&nbsp;Insofar as indemnification for liabilities arising under the Securities Act may be permitted to
directors, officers and controlling persons of the registrant pursuant to the foregoing provisions,
or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the Securities Act and is,
therefore, unenforceable. In the event that a claim for indemnification against such liabilities
(other than the payment by the registrant of expenses incurred or paid by a director, officer or
controlling person of the registrant in the successful defense of any action, suit or proceeding)
is asserted by such director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter has been settled
by controlling precedent, submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities Act and will be
governed by the final adjudication of such issue.
</DIV>




<P align="center" style="font-size: 10pt"><!-- Folio -->4<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">




<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>SIGNATURES</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has
reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has
duly caused this registration statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Danbury, State of Connecticut, on this 4th day of June, 2010.
</DIV>


<TABLE width="100%" border="0" cellspacing="0" cellpadding="0" style="font-size: 10pt">
<TR>
    <TD width="48%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
    <TD width="15%">&nbsp;</TD>
</TR>
<TR>
    <TD valign="top" align="left">&nbsp;</TD>
    <TD colspan="3" align="left">ATMI, INC.<BR>
&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD valign="top">By:&nbsp;&nbsp;</TD>
    <TD colspan="2" style="border-bottom: 1px solid #000000" align="left">/s/ Douglas A. Neugold
&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD valign="top">Name:&nbsp;&nbsp;</TD>
    <TD align="left">Douglas A. Neugold&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR><TR>
    <TD align="left">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD valign="top">Title:&nbsp;&nbsp;</TD>
    <TD align="left">President and <br>
Chief Executive Officer&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>
<TR>
    <TD colspan="5">&nbsp;</TD>
</TR>
</TABLE>

<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>POWER OF ATTORNEY</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below constitutes and
appoints Douglas A. Neugold and Timothy C. Carlson and each of them his or her true and lawful
attorneys-in-fact and agents, each acting alone, with full and several power of substitution, for
him or her and in his or her name, place and stead, in any and all capacities, to sign any or all
amendments, including post-effective amendments, and supplements to this registration statement,
and to file the same, with all exhibits thereunto and other documents in connection therewith, with
the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, full power
and authority to do and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as they or he might or could do in
person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or his or her
substitute or substitutes, may lawfully do or cause to be done by virtue hereof.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Pursuant to the requirements of the Securities Act of 1933, this registration statement has been
signed by the following persons in the capacities and on the date indicated.
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="40%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="30%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="25%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center" style="border-bottom: 1px solid #000000"><B>Name</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" style="border-bottom: 1px solid #000000"><B>Capacity</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" style="border-bottom: 1px solid #000000"><B>Date</B></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->

<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B><I>(i)&nbsp;Principal Executive Officer:</I></B></DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Douglas A. Neugold
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Douglas A. Neugold
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director, President and<br>
Chief Executive Officer
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">June&nbsp;4, 2010</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B><I>(ii)&nbsp;Principal Financial and
Accounting Officer:</I></B></DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Timothy C. Carlson
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Timothy C. Carlson
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Executive Vice President,<br>
Chief Financial Officer and<br>
Treasurer
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">June&nbsp;4, 2010</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt"><!-- Folio -->5<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="40%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="30%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="25%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center" style="border-bottom: 1px solid #000000"><B>Name</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" style="border-bottom: 1px solid #000000"><B>Capacity</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center" style="border-bottom: 1px solid #000000"><B>Date</B></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B><I>(iii)&nbsp;A Majority of the
Board of Directors:</I></B></DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Eugene G. Banucci, Ph.D.
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Eugene G. Banucci, Ph.D.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Chairman of the Board<br> and Director
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">June&nbsp;4, 2010</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Mark A. Adley
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Mark A. Adley
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">June&nbsp;4, 2010</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Robert S. Hillas
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Robert S. Hillas
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">June&nbsp;4, 2010</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Stephen H. Mahle
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Stephen H. Mahle
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">June&nbsp;4, 2010</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ C. Douglas Marsh
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
C. Douglas Marsh
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">June&nbsp;4, 2010</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Cheryl L. Shavers, Ph.D.
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Cheryl L. Shavers, Ph.D.
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">June&nbsp;4, 2010</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt"><!-- Folio -->6<!-- /Folio -->
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>INDEX TO EXHIBITS</B>
</DIV>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="4%">&nbsp;</TD>
    <TD width="3%">&nbsp;</TD>
    <TD width="93%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Exhibit</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Description</B></TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left"><B>Number</B></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.1
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Restated Certificate of Incorporation (1)</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.2
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Amended and Restated Bylaws (2)</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.3
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Rights Agreement, dated as of October&nbsp;13, 2000, between
ATMI, Inc. and Fleet National Bank, as Rights Agent (3)</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.4
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">ATMI, Inc. 2010 Stock Plan (filed herewith)</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">5.1
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Opinion of Wiggin and Dana LLP (filed herewith)</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.1
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Consent of Independent Registered
Public Accounting Firm (filed herewith)</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.2
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Consent of Counsel (included in Exhibit&nbsp;5.1)</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">24.1
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Power of Attorney (included in signature page)</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="3%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left">(1)</TD>
    <TD>&nbsp;</TD>
    <TD>Incorporated by reference to Exhibit 3(i) to the Company&#146;s Current Report on Form 8-K filed
with the Securities and Exchange Commission on August&nbsp;3, 2005.</TD>
</TR>

<TR style="font-size: 3pt"><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD nowrap align="left">(2)</TD>
    <TD>&nbsp;</TD>
    <TD>Incorporated by reference to Exhibit&nbsp;3.1 to the Company&#146;s Current Report on Form 8-K filed with
the Securities and Exchange Commission on December&nbsp;18, 2008.</TD>
</TR>

<TR style="font-size: 3pt"><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD nowrap align="left">(3)</TD>
    <TD>&nbsp;</TD>
    <TD>Incorporated by reference to Exhibit&nbsp;4.02 to the
Company&#146;s Annual Report on Form 10-K filed with
the Securities and Exchange Commission on February&nbsp;20, 2009.</TD>
</TR>

</TABLE>




<P align="center" style="font-size: 10pt"><!-- Folio -->7<!-- /Folio -->
</DIV>



</BODY>
</HTML>
[{"type": "S-8", "sequence": "1", "filename": "y03595sv8.htm", "description": "FORM S-8", "secsgml_size_bytes": 48115}]
{"company-data": {"conformed-name": "ATMI INC", "cik": "0001041577", "assigned-sic": "2810", "irs-number": "061481060", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-167318", "film-number": "10878431"}, "business-address": {"street1": "7 COMMERCE DRIVE", "city": "DANBURY", "state": "CT", "zip": "06810-4169", "phone": "2037941100"}, "mail-address": {"street1": "7 COMMERCE DRVIE", "city": "DANBURY", "state": "CT", "zip": "06810-4169"}, "former-company": {"former-conformed-name": "ATMI HOLDINGS INC", "date-changed": "19970625"}}
sv8
As filed with the Securities and Exchange Commission on June 4, 2010
Registration Statement No. 333-
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, DC 20549
FORM S-8
REGISTRATION STATEMENT
UNDER THE SECURITIES ACT OF 1933
ATMI, INC.
(Exact name of registrant as specified in its charter)
Delaware
(State or other jurisdiction of
incorporation or organization)
06-1481060
(IRS Employer
Identification No.)
7 Commerce Drive
Danbury, Connecticut 06810
(Address of Principal Executive Offices)
ATMI, Inc. 2010 Stock Plan
(Full Title of the Plan)
Ellen T. Harmon, Esq.
Executive Vice President and Chief Legal Officer
ATMI, Inc.
7 Commerce Drive
Danbury, Connecticut 06810
(203) 794-1100
(Name, Address and Telephone Number, including area code, of Agent for Service)
Copies
of all communications, including all communications sent to agent for service should be sent to:
Michael Grundei, Esq.
Wiggin and Dana LLP
400 Atlantic Street
Stamford, Connecticut 06901
(203) 363-7600
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated
filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large
accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the
Exchange Act.
(Check one):
Large accelerated filer
o
Accelerated
filer
þ
Non-accelerated filer
o
(Do not check if a smaller reporting company)
Smaller reporting company
o
CALCULATION OF REGISTRATION FEE
Proposed Maximum
Proposed Maximum
Title of Securities
Amount to be
Offering
Aggregate Offering
Amount of
to be Registered
Registered(1)
Price Per Share(2)
Price
Registration Fee
Common Stock, $.01
par value
per share
3,000,000 shares
$15.785
$47,355,000.00
$3,376.41
(1)
Plus such additional indeterminable number of shares as may be required pursuant to the ATMI,
Inc. 2010 Stock Plan in the event of a stock dividend, stock split, recapitalization or other
similar change in the Common Stock.
(2)
Computed in accordance with Rules 457(c) and 457(h) under the Securities Act of 1933, as
amended, such computation is based on $15.785 per share (the average of the high and low prices as
reported on the NASDAQ Global Select Market on June 1, 2010).
PART II
INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
Item 3. Incorporation of Documents by Reference.
There are hereby incorporated by reference in this Registration Statement of ATMI, Inc. (the
"Company") the following documents and information heretofore filed under the Securities Exchange
Act of 1934, as amended (the "Exchange Act") with the Securities and Exchange Commission:
(a)
The Company's Annual Report on Form 10-K for the fiscal year ended December 31,
2009;
(b)
The Company's Quarterly Report on Form 10-Q for the quarter ended March 31, 2010;
(c)
The Company's Current Reports on Form 8-K filed with the Securities and Exchange
Commission on April 9, 2010 and May 26, 2010;
(d)
The Company's Proxy Statement filed with the Securities and Exchange Commission on
April 9, 2010;
(e)
The description of the common stock of the Company's predecessor, Advanced
Technology Materials, Inc. ("ATM"), as set forth in ATM's Registration Statement on Form
8-A, filed on November 1, 1993, which description was amended on Form 8-A/A on November
11, 1993, and any amendment or report filed for the purpose of further updating such
description.
All documents filed by the Company pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange
Act after the date of this Registration Statement and prior to the filing of a post-effective
amendment which indicates that all securities offered have been sold or which deregisters all
securities then remaining unsold, shall be deemed to be incorporated by reference in this
Registration Statement and to be part hereof from the date of filing such documents.
The Company will provide, without charge to each person, including any beneficial owner, to whom
this document is delivered, upon written or oral request of such person, a copy of any or all of
the documents incorporated herein by reference (other than exhibits, unless such exhibits
specifically are incorporated by reference into such documents or this document). Requests for such
documents submitted in writing, should be addressed to the office of the corporate Secretary, ATMI,
Inc., 7 Commerce Drive, Danbury, Connecticut 06810. Oral requests should be made by telephone to
the corporate Secretary at (203) 794-1100.
Item 4. Description of Securities.
Not applicable.
Item 5. Interests of Named Experts and Counsel.
Not applicable.
Item 6. Indemnification of Directors and Officers.
Section 145 of the General Corporation Law of the State of Delaware ("Delaware Law") empowers a
Delaware corporation to indemnify any persons who are, or are threatened to be made, parties to any
pending or completed action, suit or proceeding, whether civil, criminal, administrative or
investigative (other than an action by or in the right of such corporation), by reason of the fact
that such person is or was a director,
officer, employee or agent of such corporation, or is or was serving at the request of such
corporation as a director, officer, employee or agent of another corporation or enterprise. The
indemnity may include expenses (including attorneys' fees), judgments, fines and amounts paid in
settlement actually and reasonably incurred by such person in connection with such action, suit or
proceeding, provided that such person acted in good faith and in a manner he or she reasonably
believed to be in or not opposed to the corporation's best interests, and, for criminal actions or
proceedings, had no reasonable cause to believe his or her conduct was unlawful. A Delaware
corporation may indemnify officers and directors against expenses (including attorney's fees) in
connection with the defense or settlement of an action by or in the right of the corporation under
the same conditions, except that no indemnification is permitted without judicial approval if the
officer or director is adjudged to be liable to the corporation. Where an officer or director is
successful on the merits or otherwise in the defense of any action referred to above, the
corporation must indemnify him or her against the expenses which such officer or director actually
and reasonably incurred.
The Company's Restated Certificate of Incorporation (the "Charter") provides for the
indemnification of each director of the Company to the fullest extent permitted by Delaware Law.
The Charter also provides that, to the fullest extent permitted by Delaware Law, no director of the
Company shall be liable to the Company or any of its shareholders for monetary damages for breach
of fiduciary duty as a director. The Company's Amended and Restated Bylaws provide further that
the Company shall indemnify any director or officer who was or is a party to or is involved in, or
is threatened to be made a party to or involved in, any third party proceeding by reason of the
fact that such person was or is a director or an officer, against expenses, judgments, fines and
amounts paid in settlement actually and reasonably incurred by such person in connection with
investigating, defending, settling, being a witness in, or participating in (including on appeal),
or preparing for any of the foregoing, if such person acted in good faith and in a manner such
person reasonably believed to be in or not opposed to the best interests of the Company and, with
respect to any criminal third party proceeding, had no reasonable cause to believe such conduct was
unlawful. In addition, the Amended and Restated Bylaws provide that the Company shall indemnify
any director or officer who was or is a party to or is involved in, or is threatened to be made a
party to or involved in, any corporate proceeding by reason of the fact that such person was or is
a director or officer of the Company, against expenses actually and reasonably incurred by such
person in connection with investigating, defending, settling, being a witness in, or participating
in (including on appeal) such corporate proceeding, or preparing for any of the foregoing, if such
person acted in good faith and in a manner such person reasonably believed to be in or not opposed
to the best interests of the Company; provided, however, that no indemnification shall be made in
respect of any claim, issue or matter as to which such person shall have been adjudged to be liable
to the Company except and only to the extent that the Court of Chancery of the State of Delaware or
the court in which such corporate proceeding was brought shall determine upon application that,
despite the adjudication of liability, but in view of all the circumstances of the case, such
person is fairly and reasonably entitled to indemnity for such expenses which the Court of Chancery
of the State of Delaware or such other court shall deem proper.
Section 145 of Delaware Law also empowers corporations to purchase and maintain insurance on behalf
of any person who is or was an officer or director of the corporation whether or not the
corporation would have the power to indemnify such officer or director against such liability under
the provisions of Section 145. The Company has purchased and maintains a directors' and officers'
liability policy for such purposes.
Item 7. Exemption From Registration Claimed.
Not applicable.
Item 8. Exhibits.
4.1 Restated Certificate of Incorporation (1)
4.2 Amended and Restated Bylaws (2)
2
4.3 Rights Agreement, dated as of October 13, 2000, between ATMI, Inc. and Fleet National Bank,
as Rights Agent (3)
4.4 ATMI,
Inc. 2010 Stock Plan (filed herewith)
5.1 Opinion of Wiggin and Dana LLP (filed herewith)
23.1
Consent of Independent Registered Public Accounting Firm (filed herewith)
23.2 Consent of Counsel (included in Exhibit 5.1)
24.1 Power of Attorney (included in signature page)
(1)
Incorporated by reference to Exhibit 3(i) to the Company's Current Report on Form 8-K filed
with the Securities and Exchange Commission on August 3, 2005.
(2)
Incorporated by reference to Exhibit 3.1 to the Company's Current Report on Form 8-K filed with
the Securities and Exchange Commission on December 18, 2008.
(3)
Incorporated by reference to Exhibit 4.02 to the
Company's Annual Report on Form 10-K filed with
the Securities and Exchange Commission on February 20, 2009.
Item 9. Undertakings.
(a) The undersigned registrant hereby undertakes:
(1) To file, during any period in which offers or sales are being made, a post-effective
amendment to this registration statement:
(i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933,
as amended (the "Securities Act");
(ii) To reflect in the prospectus any facts or events arising after the effective date of
the registration statement (or the most recent post-effective amendment thereof) which,
individually or in the aggregate, represent a fundamental change in the information set forth
in the registration statement. Notwithstanding the foregoing, any increase or decrease in
volume of securities offered (if the total dollar value of securities offered would not exceed
that which was registered) and any deviation from the low or high end of the estimated maximum
offering range may be reflected in the form of prospectus filed with the Commission pursuant
to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a
20 percent change in the maximum aggregate offering price set forth in the "Calculation of
Registration Fee" table in the effective registration statement.
(iii) To include any material information with respect to the plan of distribution not
previously disclosed in the registration statement or any material change to such information
in the registration statement;
Provided, however
, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the information
required to be included in a post-effective amendment by those paragraphs is contained in
reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or
Section 15(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act") that are
incorporated by reference in the registration statement.
(2) That, for the purpose of determining any liability under the Securities Act, each such
post-effective amendment shall be deemed to be a new registration statement relating to the
securities offered herein, and the offering of such securities at that time shall be deemed to
be the initial bona fide offering thereof.
(3) To remove from registration by means of a post-effective amendment any of the securities
being registered which remain unsold at the termination of the offering.
3
(4) That, for the purpose of determining liability of the registrant under the Securities Act
to any purchaser in the initial distribution of the securities, the undersigned registrant
undertakes that in a primary offering of securities of the undersigned registrant pursuant to
this registration statement, regardless of the underwriting method used to sell the securities
to the purchaser, if the securities are offered or sold to such purchaser by means of any of
the following communications, the undersigned registrant will be a seller to the purchaser and
will be considered to offer or sell such securities to such purchaser: (i) any preliminary
prospectus or prospectus of the undersigned registrant relating to the offering required to be
filed pursuant to Rule 424; (ii) any free writing prospectus relating to the offering prepared
by or on behalf of the undersigned registrant or used or referred to by the undersigned
registrant; (iii) the portion of any other free writing prospectus relating to the offering
containing material information about the undersigned registrant or its securities provided by
or on behalf of the undersigned registrant; and (iv) any other communication that is an offer
in the offering made by the undersigned registrant to the purchaser.
(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability
under the Securities Act, each filing of the registrant's annual report pursuant to Section 13(a)
or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by
reference in the Registration Statement shall be deemed to be a new registration statement relating
to the securities offered herein, and the offering of such securities at that time shall be deemed
to be the initial bona fide offering thereof.
(c) Insofar as indemnification for liabilities arising under the Securities Act may be permitted to
directors, officers and controlling persons of the registrant pursuant to the foregoing provisions,
or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the Securities Act and is,
therefore, unenforceable. In the event that a claim for indemnification against such liabilities
(other than the payment by the registrant of expenses incurred or paid by a director, officer or
controlling person of the registrant in the successful defense of any action, suit or proceeding)
is asserted by such director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter has been settled
by controlling precedent, submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities Act and will be
governed by the final adjudication of such issue.
4
SIGNATURES
Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has
reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has
duly caused this registration statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Danbury, State of Connecticut, on this 4th day of June, 2010.
ATMI, INC.
By:
/s/ Douglas A. Neugold
Name:
Douglas A. Neugold
Title:
President and
Chief Executive Officer
POWER OF ATTORNEY
KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below constitutes and
appoints Douglas A. Neugold and Timothy C. Carlson and each of them his or her true and lawful
attorneys-in-fact and agents, each acting alone, with full and several power of substitution, for
him or her and in his or her name, place and stead, in any and all capacities, to sign any or all
amendments, including post-effective amendments, and supplements to this registration statement,
and to file the same, with all exhibits thereunto and other documents in connection therewith, with
the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, full power
and authority to do and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as they or he might or could do in
person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or his or her
substitute or substitutes, may lawfully do or cause to be done by virtue hereof.
Pursuant to the requirements of the Securities Act of 1933, this registration statement has been
signed by the following persons in the capacities and on the date indicated.
Name
Capacity
Date
(i) Principal Executive Officer:
/s/ Douglas A. Neugold
Douglas A. Neugold
Director, President and
Chief Executive Officer
June 4, 2010
(ii) Principal Financial and
Accounting Officer:
/s/ Timothy C. Carlson
Timothy C. Carlson
Executive Vice President,
Chief Financial Officer and
Treasurer
June 4, 2010
5
Name
Capacity
Date
(iii) A Majority of the
Board of Directors:
/s/ Eugene G. Banucci, Ph.D.
Eugene G. Banucci, Ph.D.
Chairman of the Board
and Director
June 4, 2010
/s/ Mark A. Adley
Mark A. Adley
Director
June 4, 2010
/s/ Robert S. Hillas
Robert S. Hillas
Director
June 4, 2010
/s/ Stephen H. Mahle
Stephen H. Mahle
Director
June 4, 2010
/s/ C. Douglas Marsh
C. Douglas Marsh
Director
June 4, 2010
/s/ Cheryl L. Shavers, Ph.D.
Cheryl L. Shavers, Ph.D.
Director
June 4, 2010
6
INDEX TO EXHIBITS
Exhibit
Description
Number
4.1
Restated Certificate of Incorporation (1)
4.2
Amended and Restated Bylaws (2)
4.3
Rights Agreement, dated as of October 13, 2000, between
ATMI, Inc. and Fleet National Bank, as Rights Agent (3)
4.4
ATMI, Inc. 2010 Stock Plan (filed herewith)
5.1
Opinion of Wiggin and Dana LLP (filed herewith)
23.1
Consent of Independent Registered
Public Accounting Firm (filed herewith)
23.2
Consent of Counsel (included in Exhibit 5.1)
24.1
Power of Attorney (included in signature page)
(1)
Incorporated by reference to Exhibit 3(i) to the Company's Current Report on Form 8-K filed
with the Securities and Exchange Commission on August 3, 2005.
(2)
Incorporated by reference to Exhibit 3.1 to the Company's Current Report on Form 8-K filed with
the Securities and Exchange Commission on December 18, 2008.
(3)
Incorporated by reference to Exhibit 4.02 to the
Company's Annual Report on Form 10-K filed with
the Securities and Exchange Commission on February 20, 2009.
7