As filed with the Securities and Exchange Commission on September 22, 2000.
                                                           Registration No. 333-
          -------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549
                                 ---------------

                                    FORM S-8
                             Registration Statement
                                      Under
                           The Securities Act of 1933
                                 ---------------

                           THERMO ELECTRON CORPORATION
             (Exact name of registrant as specified in its charter)
                                 ---------------

      DELAWARE                                            04-2209186
(State or other jurisdiction of                           (I.R.S. Employer
 incorporation or organization)                           Identification Number)

                                 81 Wyman Street
                        Waltham, Massachusetts 02454-9046
               (Address of Principal Executive Offices) (Zip Code)

                THERMO TERRATECH INC. DIRECTORS STOCK OPTION PLAN

               THERMO ELECTRON CORPORATION - THERMO TERRATECH INC.
                     NONQUALIFIED STOCK OPTION PLAN (1996)

             THERMO ELECTRON CORPORATION DIRECTORS STOCK OPTION PLAN
                           (THERMO TERRATECH SHARES)

           THERMO TERRATECH INC. DIRECTORS DEFERRED COMPENSATION PLAN

              THERMO TERRATECH INC. NONQUALIFIED STOCK OPTION PLAN

               THERMO ELECTRON CORPORATION - THERMO TERRATECH INC.
                     NONQUALIFIED STOCK OPTION PLAN (1986)

                   THERMO TERRATECH INC. EQUITY INCENTIVE PLAN

          THERMO INSTRUMENT SYSTEMS INC. EMPLOYEES' STOCK PURCHASE PLAN


                           (Full Titles of the Plans)



<PAGE>


                          Sandra L. Lambert, Secretary
                           Thermo Electron Corporation
                                 81 Wyman Street
                                 P. O. Box 9046
                        Waltham, Massachusetts 02454-9046
                     (Name and Address of Agent for Service)

                                 (781) 622-1000
          (Telephone Number, Including Area Code, of Agent For Service)

                                   Copies to:
                    Seth H. Hoogasian, Esq., General Counsel
                           Thermo Electron Corporation
                                 81 Wyman Street
                                 P. O. Box 9046
                        Waltham, Massachusetts 02454-9046

                                 ---------------

                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
<S>                        <C>             <C>                     <C>              <C>
                                         Proposed
                                          Maximum           Proposed Maximum
Title of securties       Amount        Offering Price      Aggregate Offering    Amount of
to be registered    to be registered     Per Share                Price       Registration Fee
---------------     ----------------    -----------         ----------------- ----------------
Common Stock,           563,874         $25.095 (2)         $14,150,418.03 (2)     $3,736
$1.00 par value          shares
  per share               (1)
</TABLE>


         In addition, pursuant to Rule 416(c) under the Securities Act of 1933,
this Registration Statement also covers an indeterminate number of shares of
Thermo Electron's common stock as may be issuable in connection with adjustments
under the employee benefit plans described herein to reflect certain changes in
Thermo Electron's capital structure, including stock dividends or stock splits.

(1) The shares registered hereunder are divided among the various plans set
    forth below:

Thermo TerraTech Inc. Directors Stock Option Plan: 5,040 shares

Thermo Electron Corporation - Thermo TerraTech Inc. Nonqualified Stock Option
Plan (1996): 4,480 shares

Thermo Electron Corporation Directors Stock Option Plan (Thermo TerraTech
Shares): 450 shares

Thermo TerraTech Inc. Directors Deferred Compensation Plan: 14,800 shares

<PAGE>

Thermo TerraTech Inc. Nonqualified Stock Option Plan: 135,284 shares

Thermo TerraTech Inc. Equity Incentive Plan: 347,482 shares

Thermo Electron Corporation - Thermo TerraTech Inc. Nonqualified Stock Option
Plan (1986): 3,900 shares

Thermo Instrument Systems Inc. Employees' Stock Purchase Plan: 52,438 shares

(2) Estimated solely for the purpose of calculating the amount of the
    registration fee in accordance with Rule 457(h) under the Securities Act of
    1933. The calculation of the proposed maximum aggregate offering price has
    been based upon (1) the registration hereunder of an aggregate of 563,874
    shares and (2) the average of the high and low sales prices, $25.25 and
    $24.94, respectively, of Thermo Electron's common stock on the New York
    Stock Exchange on September 20, 2000 as reported in the consolidated
    transaction reporting system.



<PAGE>


                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

         The information required by Part I is included in documents sent or
given to the respective participants in the plans registered hereunder pursuant
to Rule 428(b)(1) under the Securities Act of 1933, as amended.


                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

         Thermo Electron is subject to the informational and reporting
requirements of Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange
Act of 1934, as amended, and in accordance therewith files reports, proxy
statements and other information with the Securities and Exchange Commission.
The following documents, which are on file with the Commission, are incorporated
in this Registration Statement by reference:

         (a) Thermo Electron's Annual Report on Form 10-K for the fiscal year
             ended January 1, 2000, as amended.

         (b) Thermo Electron's Quarterly Report on Form 10-Q for the quarter
             ended April 1, 2000.

         (c) Thermo Electron's Quarterly Report on Form 10-Q for the quarter
             ended July 1, 2000.

         (d) Thermo Electron's Current Reports on Form 8-K filed with the
             Commission on February 1, 2000, May 2, 2000, June 14, 2000, June
             30, 2000, July 11, 2000 and August 3, 2000.

         (e) The description of the common stock which is contained in Thermo
             Electron's Registration Statement on Form 8-A filed under the
             Exchange Act, as such description may be amended from time to time.

         (f) The description of Thermo Electron's Preferred Stock Purchase
             Rights which is contained in Thermo Electron's Registration
             Statement on Form 8-A filed under the Exchange Act, as such
             description may be amended from time to time.


         All reports or proxy statements filed by Thermo Electron pursuant to
Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act subsequent to the date
of this Registration Statement and prior to the filing of a post-effective
amendment that indicates that all securities offered herein have been sold, or
that deregisters all such securities then remaining unsold, shall be deemed to
be incorporated by reference in this Registration Statement and to be a part
hereof from the respective dates of filing of such documents.

<PAGE>

Item 4.  Description of Securities.

         Not applicable.

Item 5.  Interests of Named Experts and Counsel.

         The validity of the common stock offered hereby has been passed upon by
Seth H. Hoogasian, Esq., General Counsel of Thermo Electron. Mr. Hoogasian is a
full-time employee of Thermo Electron, is an officer of Thermo Electron, and
owns or has the right to acquire 432,413 shares of common stock and 41,100
shares of the common stock of Thermo Electron's subsidiaries.

Item 6.  Indemnification of Directors and Officers.

         The Delaware General Corporation Law and Thermo Electron's Certificate
of Incorporation and By-Laws limit the monetary liability of directors to Thermo
Electron and to its stockholders and provide for indemnification of Thermo
Electron's officers and directors for liabilities and expenses that they may
incur in such capacities. In general, officers and directors are indemnified
with respect to actions taken in good faith in a manner reasonably believed to
be in, or not opposed to, the best interests of Thermo Electron and, with
respect to any criminal action or proceeding, actions that the indemnitee had no
reasonable cause to believe were unlawful. Thermo Electron also has
indemnification agreements with its directors and officers that provide for the
maximum indemnification allowed by law.

         Thermo Electron has an insurance policy which insures the directors and
officers of Thermo Electron and its subsidiaries against certain liabilities
which might be incurred in connection with the performance of their duties.

Item 7.  Exemption from Registration Claimed.

         Not Applicable.

Item 8.  Exhibits.

         The Exhibit Index immediately preceding the exhibits is attached hereto
and incorporated herein by reference.

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;

                           (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

<PAGE>
         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 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 periodic reports filed with or furnished to
the Commission by Thermo Electron pursuant to Section 13 or Section 15(d) of the
Securities Exchange Act of 1934 that are incorporated by reference in the
registration statement.

                  (2) That, for the purpose of determining any liability under
the Securities Act of 1933, each such post-effective amendment shall be deemed
to be a new registration statement relating to the securities offered therein,
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.

         (b) The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of
Thermo Electron's annual report pursuant to Section 13(a) or 15(d) of the
Securities Exchange Act of 1934 (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to Section 15(d) of the
Securities Exchange Act of 1934) that is incorporated by reference in the
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, 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 of 1933 may be permitted to directors, officers and controlling
persons of Thermo Electron pursuant to the foregoing provisions, or otherwise,
Thermo Electron has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by Thermo
Electron of expenses incurred or paid by a director, officer or controlling
person of Thermo Electron 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, Thermo Electron 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 Act and will
be governed by the final adjudication of such issue.


<PAGE>


                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, Thermo
Electron 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 Waltham, Commonwealth of Massachusetts, on this 22nd
day of September, 2000.

                                   THERMO ELECTRON CORPORATION


                                   By:   /s/ Richard F. Syron
                                         ----------------------------
                                         Richard F. Syron
                                   Its:  President, Chief Executive Officer and
                                         Chairman of the Board of Directors


                                POWER OF ATTORNEY

         Each of the undersigned Directors and Officers of Thermo Electron
Corporation hereby appoints Theo Melas-Kyriazi, Kenneth J. Apicerno, Seth H.
Hoogasian and Sandra L. Lambert, and each of them, his true and lawful
attorneys-in-fact and agents, with full power of substitution, for him and in
his name, place and stead, in any and all capacities, to sign any and all
amendments (including post-effective amendments) to this Registration Statement,
and to file the same, with all exhibits thereto, and all documents in connection
therewith, with the Securities and Exchange Commission, granting unto said
attorneys-in-fact and agents, and each of them, 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 he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents or any of them, or their or his substitute or
substitutes, may lawfully do or cause to be done by virtue thereof.

         Pursuant  to the  requirements  of the  Securities  Act of  1933,  this
Registration  Statement  has been signed below by the  following  persons in the
capacities and on the dates indicated:

<TABLE>
<CAPTION>
<S>         <C>                      <C>                                          <C>
         Signature                  Title                                        Date
         ---------                  -----                                        ----
                                 President, Chief Executive Officer
/s/ Richard F. Syron             and Director (Principal Executive
-------------------------------  Officer)                                  September 22, 2000
Richard F. Syron

                                 Vice President and Chief Financial
/s/ Theo Melas-Kyriazi           Officer (Principal Financial and
-------------------------------- Accounting Officer)                       September 22, 2000
Theo Melas-Kyriazi

</TABLE>


<PAGE>
<TABLE>
<CAPTION>
<S>         <C>                      <C>                                          <C>
/s/ Samuel W. Bodman
-------------------------------  Director                                  September 22, 2000
Samuel W. Bodman


/s/ Peter O. Crisp
-------------------------------- Director                                  September 22, 2000
Peter O. Crisp


/s/ Elias P. Gyftopoulos
-------------------------------  Director                                  September 22, 2000
Elias P. Gyftopoulos



-------------------------------- Director                                  September 22, 2000
Frank Jungers


/s/ Jim P. Manzi
-------------------------------  Director                                  September 22, 2000
Jim P. Manzi



-------------------------------- Director                                  September 22, 2000
Robert A. McCabe


/s/ Hutham S. Olayan
-------------------------------  Director                                  September 22, 2000
Hutham S. Olayan



-------------------------------- Director                                  September 22, 2000
Robert W. O'Leary

</TABLE>





<PAGE>


                                  EXHIBIT INDEX


                  Exhibit
                  Number            Description
                  ------            -----------

                  5               Opinion of Seth H. Hoogasian, Esq.

                  23.1            Consent of Arthur Andersen LLP

                  23.2            Consent of Seth H. Hoogasian, Esq.
                                  (contained in his opinion filed as Exhibit 5).

                  24              Power of Attorney (see signature pages to
                                  this Registration Statement).



<PAGE>





                                                                      EXHIBIT 5



                           Thermo Electron Corporation
                                 81 Wyman Street
                        Waltham, Massachusetts 02454-9046




                                                             September 22, 2000

Thermo Electron Corporation
81 Wyman Street
Waltham, Massachusetts 02454-9046

Re:      Registration Statement on Form S-8 Relating to 563,874 Shares of the
         Common Stock, $1.00 par value, of Thermo Electron Corporation
         -------------------------------------------------------------

Dear Sirs:

         I am General Counsel to Thermo Electron Corporation, a Delaware
corporation (the "Company"), and have acted as counsel in connection with the
registration under the Securities Act of 1933, as amended, on Form S-8 (the
"Registration Statement"), of 563,874 shares of Thermo Electron's Common Stock,
$1.00 par value per share (the "Shares") subject to the stock plans listed on
Schedule 1 hereto (collectively, the "Plans").

         I or a member of my legal staff have reviewed the corporate proceedings
taken by Thermo Electron with respect to the authorization of the issuance of
the Shares. I or a member of my legal staff have also examined and relied upon
originals or copies, certified or otherwise authenticated to my satisfaction, of
all corporate records, documents, agreements or other instruments of Thermo
Electron and have made all investigations of law and have discussed with Thermo
Electron's representatives all questions of fact that I have deemed necessary or
appropriate.

         Based upon and subject to the foregoing, I am of the opinion that:

         1. Thermo Electron is a corporation validly existing and in corporate
good standing under the laws of the State of Delaware.

         2. The issuance and sale of the Shares as contemplated in the
Registration Statement have been duly authorized by Thermo Electron.

         3. The Shares, when issued and sold in accordance with the provisions
of the respective Plans, will be validly issued, fully paid and nonassessable.

<PAGE>

         This opinion is limited to the applicable provisions of the Delaware
Constitution, the General Corporation Law of the State of Delaware ("Delaware
Law") and reported judicial decisions interpreting Delaware Law.

         I hereby  consent  to the  filing of this  opinion  as Exhibit 5 to the
Registration Statement.

                                                  Very truly yours,



                                                  /s/ Seth H. Hoogasian
                                                  -----------------------
                                                  Seth H. Hoogasian
                                                  General Counsel


<PAGE>


                                   SCHEDULE 1


                THERMO TERRATECH INC. DIRECTORS STOCK OPTION PLAN

               THERMO ELECTRON CORPORATION - THERMO TERRATECH INC.
                     NONQUALIFIED STOCK OPTION PLAN (1996)

             THERMO ELECTRON CORPORATION DIRECTORS STOCK OPTION PLAN
                           (THERMO TERRATECH SHARES)

           THERMO TERRATECH INC. DIRECTORS DEFERRED COMPENSATION PLAN

       THERMO TERRATECH INC. NONQUALIFIED AND INCENTIVE STOCK OPTION PLAN

               THERMO ELECTRON CORPORATION - THERMO TERRATECH INC.
                     NONQUALIFIED STOCK OPTION PLAN (1986)

                   THERMO TERRATECH INC. EQUITY INCENTIVE PLAN

          THERMO INSTRUMENT SYSTEMS INC. EMPLOYEES' STOCK PURCHASE PLAN




<PAGE>


                                                                  Exhibit 23.1






                    Consent of Independent Public Accountants


         As independent public accountants, we hereby consent to the
incorporation by reference in this registration statement on Form S-8 of our
report dated February 17, 2000 (except for the matters discussed in Note 17, as
to which the date is March 7, 2000), included in Thermo Electron Corporation's
Annual Report on Form 10-K for the year ended January 1, 2000, and to all
references to our Firm included in this registration statement.


                                                           Arthur Andersen LLP



Boston, Massachusetts
September 21, 2000
[{"type": "S-8", "sequence": "1", "filename": "0001.txt", "description": "FORM S-8", "secsgml_size_bytes": 23143}]
{"company-data": {"conformed-name": "THERMO ELECTRON CORP", "cik": "0000097745", "assigned-sic": "3829", "irs-number": "042209186", "state-of-incorporation": "DE", "fiscal-year-end": "0102"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-46408", "film-number": "727216"}, "business-address": {"street1": "81 WYMAN ST", "street2": "P O BOX 9046", "city": "WALTHAM", "state": "MA", "zip": "02454-9046", "phone": "7816221000"}}
As filed with the Securities and Exchange Commission on September 22, 2000.
                                                           Registration No. 333-
          -------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549
                                 ---------------

                                    FORM S-8
                             Registration Statement
                                      Under
                           The Securities Act of 1933
                                 ---------------

                           THERMO ELECTRON CORPORATION
             (Exact name of registrant as specified in its charter)
                                 ---------------

      DELAWARE                                            04-2209186
(State or other jurisdiction of                           (I.R.S. Employer
 incorporation or organization)                           Identification Number)

                                 81 Wyman Street
                        Waltham, Massachusetts 02454-9046
               (Address of Principal Executive Offices) (Zip Code)

                THERMO TERRATECH INC. DIRECTORS STOCK OPTION PLAN

               THERMO ELECTRON CORPORATION - THERMO TERRATECH INC.
                     NONQUALIFIED STOCK OPTION PLAN (1996)

             THERMO ELECTRON CORPORATION DIRECTORS STOCK OPTION PLAN
                           (THERMO TERRATECH SHARES)

           THERMO TERRATECH INC. DIRECTORS DEFERRED COMPENSATION PLAN

              THERMO TERRATECH INC. NONQUALIFIED STOCK OPTION PLAN

               THERMO ELECTRON CORPORATION - THERMO TERRATECH INC.
                     NONQUALIFIED STOCK OPTION PLAN (1986)

                   THERMO TERRATECH INC. EQUITY INCENTIVE PLAN

          THERMO INSTRUMENT SYSTEMS INC. EMPLOYEES' STOCK PURCHASE PLAN

                           (Full Titles of the Plans)
Sandra L. Lambert, Secretary
                           Thermo Electron Corporation
                                 81 Wyman Street
                                 P. O. Box 9046
                        Waltham, Massachusetts 02454-9046
                     (Name and Address of Agent for Service)

                                 (781) 622-1000
          (Telephone Number, Including Area Code, of Agent For Service)

                                   Copies to:
                    Seth H. Hoogasian, Esq., General Counsel
                           Thermo Electron Corporation
                                 81 Wyman Street
                                 P. O. Box 9046
                        Waltham, Massachusetts 02454-9046

                                 ---------------

                         CALCULATION OF REGISTRATION FEE
Proposed
                                          Maximum           Proposed Maximum
Title of securties       Amount        Offering Price      Aggregate Offering    Amount of
to be registered    to be registered     Per Share                Price       Registration Fee
---------------     ----------------    -----------         ----------------- ----------------
Common Stock,           563,874         $25.095 (2)         $14,150,418.03 (2)     $3,736
$1.00 par value          shares
  per share               (1)
In addition, pursuant to Rule 416(c) under the Securities Act of 1933,
this Registration Statement also covers an indeterminate number of shares of
Thermo Electron's common stock as may be issuable in connection with adjustments
under the employee benefit plans described herein to reflect certain changes in
Thermo Electron's capital structure, including stock dividends or stock splits.

(1) The shares registered hereunder are divided among the various plans set
    forth below:

Thermo TerraTech Inc. Directors Stock Option Plan: 5,040 shares

Thermo Electron Corporation - Thermo TerraTech Inc. Nonqualified Stock Option
Plan (1996): 4,480 shares

Thermo Electron Corporation Directors Stock Option Plan (Thermo TerraTech
Shares): 450 shares

Thermo TerraTech Inc. Directors Deferred Compensation Plan: 14,800 shares
Thermo TerraTech Inc. Nonqualified Stock Option Plan: 135,284 shares

Thermo TerraTech Inc. Equity Incentive Plan: 347,482 shares

Thermo Electron Corporation - Thermo TerraTech Inc. Nonqualified Stock Option
Plan (1986): 3,900 shares

Thermo Instrument Systems Inc. Employees' Stock Purchase Plan: 52,438 shares

(2) Estimated solely for the purpose of calculating the amount of the
    registration fee in accordance with Rule 457(h) under the Securities Act of
    1933. The calculation of the proposed maximum aggregate offering price has
    been based upon (1) the registration hereunder of an aggregate of 563,874
    shares and (2) the average of the high and low sales prices, $25.25 and
    $24.94, respectively, of Thermo Electron's common stock on the New York
    Stock Exchange on September 20, 2000 as reported in the consolidated
    transaction reporting system.
PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

         The information required by Part I is included in documents sent or
given to the respective participants in the plans registered hereunder pursuant
to Rule 428(b)(1) under the Securities Act of 1933, as amended.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

         Thermo Electron is subject to the informational and reporting
requirements of Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange
Act of 1934, as amended, and in accordance therewith files reports, proxy
statements and other information with the Securities and Exchange Commission.
The following documents, which are on file with the Commission, are incorporated
in this Registration Statement by reference:

         (a) Thermo Electron's Annual Report on Form 10-K for the fiscal year
             ended January 1, 2000, as amended.

         (b) Thermo Electron's Quarterly Report on Form 10-Q for the quarter
             ended April 1, 2000.

         (c) Thermo Electron's Quarterly Report on Form 10-Q for the quarter
             ended July 1, 2000.

         (d) Thermo Electron's Current Reports on Form 8-K filed with the
             Commission on February 1, 2000, May 2, 2000, June 14, 2000, June
             30, 2000, July 11, 2000 and August 3, 2000.

         (e) The description of the common stock which is contained in Thermo
             Electron's Registration Statement on Form 8-A filed under the
             Exchange Act, as such description may be amended from time to time.

         (f) The description of Thermo Electron's Preferred Stock Purchase
             Rights which is contained in Thermo Electron's Registration
             Statement on Form 8-A filed under the Exchange Act, as such
             description may be amended from time to time.

         All reports or proxy statements filed by Thermo Electron pursuant to
Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act subsequent to the date
of this Registration Statement and prior to the filing of a post-effective
amendment that indicates that all securities offered herein have been sold, or
that deregisters all such securities then remaining unsold, shall be deemed to
be incorporated by reference in this Registration Statement and to be a part
hereof from the respective dates of filing of such documents.
Item 4.  Description of Securities.

         Not applicable.

Item 5.  Interests of Named Experts and Counsel.

         The validity of the common stock offered hereby has been passed upon by
Seth H. Hoogasian, Esq., General Counsel of Thermo Electron. Mr. Hoogasian is a
full-time employee of Thermo Electron, is an officer of Thermo Electron, and
owns or has the right to acquire 432,413 shares of common stock and 41,100
shares of the common stock of Thermo Electron's subsidiaries.

Item 6.  Indemnification of Directors and Officers.

         The Delaware General Corporation Law and Thermo Electron's Certificate
of Incorporation and By-Laws limit the monetary liability of directors to Thermo
Electron and to its stockholders and provide for indemnification of Thermo
Electron's officers and directors for liabilities and expenses that they may
incur in such capacities. In general, officers and directors are indemnified
with respect to actions taken in good faith in a manner reasonably believed to
be in, or not opposed to, the best interests of Thermo Electron and, with
respect to any criminal action or proceeding, actions that the indemnitee had no
reasonable cause to believe were unlawful. Thermo Electron also has
indemnification agreements with its directors and officers that provide for the
maximum indemnification allowed by law.

         Thermo Electron has an insurance policy which insures the directors and
officers of Thermo Electron and its subsidiaries against certain liabilities
which might be incurred in connection with the performance of their duties.

Item 7.  Exemption from Registration Claimed.

         Not Applicable.

Item 8.  Exhibits.

         The Exhibit Index immediately preceding the exhibits is attached hereto
and incorporated herein by reference.

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;

                           (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 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 periodic reports filed with or furnished to
the Commission by Thermo Electron pursuant to Section 13 or Section 15(d) of the
Securities Exchange Act of 1934 that are incorporated by reference in the
registration statement.

                  (2) That, for the purpose of determining any liability under
the Securities Act of 1933, each such post-effective amendment shall be deemed
to be a new registration statement relating to the securities offered therein,
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.

         (b) The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of
Thermo Electron's annual report pursuant to Section 13(a) or 15(d) of the
Securities Exchange Act of 1934 (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to Section 15(d) of the
Securities Exchange Act of 1934) that is incorporated by reference in the
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, 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 of 1933 may be permitted to directors, officers and controlling
persons of Thermo Electron pursuant to the foregoing provisions, or otherwise,
Thermo Electron has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by Thermo
Electron of expenses incurred or paid by a director, officer or controlling
person of Thermo Electron 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, Thermo Electron 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 Act and will
be governed by the final adjudication of such issue.
SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, Thermo
Electron 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 Waltham, Commonwealth of Massachusetts, on this 22nd
day of September, 2000.

                                   THERMO ELECTRON CORPORATION

                                   By:   /s/ Richard F. Syron
                                         ----------------------------
                                         Richard F. Syron
                                   Its:  President, Chief Executive Officer and
                                         Chairman of the Board of Directors

                                POWER OF ATTORNEY

         Each of the undersigned Directors and Officers of Thermo Electron
Corporation hereby appoints Theo Melas-Kyriazi, Kenneth J. Apicerno, Seth H.
Hoogasian and Sandra L. Lambert, and each of them, his true and lawful
attorneys-in-fact and agents, with full power of substitution, for him and in
his name, place and stead, in any and all capacities, to sign any and all
amendments (including post-effective amendments) to this Registration Statement,
and to file the same, with all exhibits thereto, and all documents in connection
therewith, with the Securities and Exchange Commission, granting unto said
attorneys-in-fact and agents, and each of them, 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 he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents or any of them, or their or his substitute or
substitutes, may lawfully do or cause to be done by virtue thereof.

         Pursuant  to the  requirements  of the  Securities  Act of  1933,  this
Registration  Statement  has been signed below by the  following  persons in the
capacities and on the dates indicated:
Signature                  Title                                        Date
         ---------                  -----                                        ----
                                 President, Chief Executive Officer
/s/ Richard F. Syron             and Director (Principal Executive
-------------------------------  Officer)                                  September 22, 2000
Richard F. Syron

                                 Vice President and Chief Financial
/s/ Theo Melas-Kyriazi           Officer (Principal Financial and
-------------------------------- Accounting Officer)                       September 22, 2000
Theo Melas-Kyriazi
/s/ Samuel W. Bodman
-------------------------------  Director                                  September 22, 2000
Samuel W. Bodman

/s/ Peter O. Crisp
-------------------------------- Director                                  September 22, 2000
Peter O. Crisp

/s/ Elias P. Gyftopoulos
-------------------------------  Director                                  September 22, 2000
Elias P. Gyftopoulos

-------------------------------- Director                                  September 22, 2000
Frank Jungers

/s/ Jim P. Manzi
-------------------------------  Director                                  September 22, 2000
Jim P. Manzi

-------------------------------- Director                                  September 22, 2000
Robert A. McCabe

/s/ Hutham S. Olayan
-------------------------------  Director                                  September 22, 2000
Hutham S. Olayan

-------------------------------- Director                                  September 22, 2000
Robert W. O'Leary
EXHIBIT INDEX

                  Exhibit
                  Number            Description
                  ------            -----------

                  5               Opinion of Seth H. Hoogasian, Esq.

                  23.1            Consent of Arthur Andersen LLP

                  23.2            Consent of Seth H. Hoogasian, Esq.
                                  (contained in his opinion filed as Exhibit 5).

                  24              Power of Attorney (see signature pages to
                                  this Registration Statement).
EXHIBIT 5

                           Thermo Electron Corporation
                                 81 Wyman Street
                        Waltham, Massachusetts 02454-9046

                                                             September 22, 2000

Thermo Electron Corporation
81 Wyman Street
Waltham, Massachusetts 02454-9046

Re:      Registration Statement on Form S-8 Relating to 563,874 Shares of the
         Common Stock, $1.00 par value, of Thermo Electron Corporation
         -------------------------------------------------------------

Dear Sirs:

         I am General Counsel to Thermo Electron Corporation, a Delaware
corporation (the "Company"), and have acted as counsel in connection with the
registration under the Securities Act of 1933, as amended, on Form S-8 (the
"Registration Statement"), of 563,874 shares of Thermo Electron's Common Stock,
$1.00 par value per share (the "Shares") subject to the stock plans listed on
Schedule 1 hereto (collectively, the "Plans").

         I or a member of my legal staff have reviewed the corporate proceedings
taken by Thermo Electron with respect to the authorization of the issuance of
the Shares. I or a member of my legal staff have also examined and relied upon
originals or copies, certified or otherwise authenticated to my satisfaction, of
all corporate records, documents, agreements or other instruments of Thermo
Electron and have made all investigations of law and have discussed with Thermo
Electron's representatives all questions of fact that I have deemed necessary or
appropriate.

         Based upon and subject to the foregoing, I am of the opinion that:

         1. Thermo Electron is a corporation validly existing and in corporate
good standing under the laws of the State of Delaware.

         2. The issuance and sale of the Shares as contemplated in the
Registration Statement have been duly authorized by Thermo Electron.

         3. The Shares, when issued and sold in accordance with the provisions
of the respective Plans, will be validly issued, fully paid and nonassessable.
This opinion is limited to the applicable provisions of the Delaware
Constitution, the General Corporation Law of the State of Delaware ("Delaware
Law") and reported judicial decisions interpreting Delaware Law.

         I hereby  consent  to the  filing of this  opinion  as Exhibit 5 to the
Registration Statement.

                                                  Very truly yours,

                                                  /s/ Seth H. Hoogasian
                                                  -----------------------
                                                  Seth H. Hoogasian
                                                  General Counsel
SCHEDULE 1

                THERMO TERRATECH INC. DIRECTORS STOCK OPTION PLAN

               THERMO ELECTRON CORPORATION - THERMO TERRATECH INC.
                     NONQUALIFIED STOCK OPTION PLAN (1996)

             THERMO ELECTRON CORPORATION DIRECTORS STOCK OPTION PLAN
                           (THERMO TERRATECH SHARES)

           THERMO TERRATECH INC. DIRECTORS DEFERRED COMPENSATION PLAN

       THERMO TERRATECH INC. NONQUALIFIED AND INCENTIVE STOCK OPTION PLAN

               THERMO ELECTRON CORPORATION - THERMO TERRATECH INC.
                     NONQUALIFIED STOCK OPTION PLAN (1986)

                   THERMO TERRATECH INC. EQUITY INCENTIVE PLAN

          THERMO INSTRUMENT SYSTEMS INC. EMPLOYEES' STOCK PURCHASE PLAN
Exhibit 23.1

                    Consent of Independent Public Accountants

         As independent public accountants, we hereby consent to the
incorporation by reference in this registration statement on Form S-8 of our
report dated February 17, 2000 (except for the matters discussed in Note 17, as
to which the date is March 7, 2000), included in Thermo Electron Corporation's
Annual Report on Form 10-K for the year ended January 1, 2000, and to all
references to our Firm included in this registration statement.

                                                           Arthur Andersen LLP

Boston, Massachusetts
September 21, 2000