As filed with the Securities and Exchange Commission on January 13, 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)

        COLEMAN RESEARCH CORPORATION 401(K) EMPLOYEE STOCK OWNERSHIP PLAN

            THERMO ELECTRON CORPORATION EMPLOYEE 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

                                 ---------------
<PAGE>

                         CALCULATION OF REGISTRATION FEE


 Title of                                       Proposed
securities         Amount       Proposed        Maximum              Amount of
  to be             to be        Maximum        Aggregate          Registration
registered        registered    Offering        Offering                Fee
                                Price Per         Price
                                 Share
Common Stock,
 $1.00 par         1,310,000     $14.53125     $19,035,937.50          $5,026
 value per          shares          (2)              (2)
  share               (1)


     In addition, pursuant to Rule 416(c) under the Securities Act of 1933, this
Registration Statement also covers an indeterminate number of interests issuable
in  connection  with the Coleman  Research  Corporation  401(k)  Employee  Stock
Ownership Plan and an indeterminate  number of shares of the Registrant's Common
Stock as may be issuable  in  connection  with  adjustments  under the  employee
benefit plans described  herein to reflect  certain changes in the  Registrant's
capital structure, including stock dividends or stock splits.

(1)   Of the shares registered hereunder,  560,000 shares are issuable under the
      Coleman  Research  Corporation  401(k)  Employee Stock Ownership Plan, and
      750,000 of the shares  registered  hereunder are issuable under the Thermo
      Electron Corporation Employee Stock Purchase Plan.

(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
      1,310,000  shares and (2) the  average  of the high and low sales  prices,
      $14.75 and $14.3125, respectively, of the Registrant's Common Stock on the
      New York Stock Exchange on January 7, 2000 as reported in the consolidated
      transaction reporting system.



<PAGE>



                                EXPLANATORY NOTE

      This Registration  Statement is filed pursuant to General Instruction E of
Form S-8 in order to register  additional  securities of the same class as other
securities for which a registration  statement  relating to the Coleman Research
Corporation  401(k)  Employee Stock  Ownership Plan (the "Coleman Plan") and the
Thermo  Electron  Corporation  Employee  Stock  Purchase  Plan (the  "ESPP")  is
effective.

     On January 10, 1997, the Company filed a registration statement on Form S-8
(Reg. No.  333-19535) to register an aggregate of 250,000 shares of Common Stock
reserved for issuance under the Coleman Plan. The addition of this  Registration
Statement  brings the total number of shares  registered  for issuance under the
Coleman Plan to 810,000. In addition,  on November 16, 1990, the Company filed a
registration  statement on Form S-8 (Reg. No. 33-37865) to register an aggregate
of 400,000  shares of Common Stock  reserved for  issuance  under the ESPP.  The
addition of this Registration  Statement,  together with the effect of 3:2 stock
splits in 1993,  1995 and 1996 brings the total  number of shares that have been
registered  for  issuance  under  the ESPP to  2,100,000.  The  contents  of the
previously filed  registration  statements  relating to the Coleman Plan and the
ESPP are  incorporated  herein by  reference  except  for the items that are set
forth below.  Pursuant to Instruction E, this  Registration  Statement  contains
such  information  required  by Form S-8 that is not  otherwise  included in the
previous registration statement.

                                     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  respective  plans  pursuant  to  Rule
428(b)(1) under the Securities Act of 1933, as amended (the  "Securities  Act").
As used in this  Registration  Statement,  the terms  "Registrant"  or "Company"
refer to Thermo Electron Corporation.


                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

      The Registrant 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 (the  "Exchange  Act"),  and in accordance  therewith  files reports,
proxy  statements  and  other  information  with  the  Securities  and  Exchange
Commission (the "Commission").  The following documents,  which are on file with
the Commission, are incorporated in this Registration Statement by reference:

            (a)   The  Company's  Annual Report on Form 10-K for the fiscal year
                  ended January 2, 1999.

            (b)   The  Company's  Current  Report  on Form  8-K  filed  with the
                  Commission on January 8, 1999.
<PAGE>

            (c)   The  Company's  Current  Report  on Form  8-K  filed  with the
                  Commission on March 9, 1999.

            (d)   The  Company's  Current  Report  on Form  8-K  filed  with the
                  Commission on March 15, 1999.

            (e)   The  Company's  Quarterly  Report on Form 10-Q for the quarter
                  ended April 3, 1999.

            (f)   The  Company's  Current  Report  on Form  8-K  filed  with the
                  Commission on May 25, 1999.

            (g)   The  Company's  Quarterly  Report on Form 10-Q for the quarter
                  ended July 3, 1999.

            (h)   The  Company's  Quarterly  Report on Form 10-Q for the quarter
                  ended October 2, 1999.

            (i)   The  Company's  Current  Report  on Form  8-K  filed  with the
                  Commission on December 21, 1999.

            (j)   The  description of the Common Stock which is contained in the
                  Company'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 the Company 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 the Company.  Mr.  Hoogasian is a
full-time employee of the Company, is an officer of the Company, and owns or has
the right to acquire  348,944  shares of Common Stock and 162,177  shares of the
Company's subsidiaries.
<PAGE>

Item 6.  Indemnification of Directors and Officers.

      The Delaware  General  Corporation  Law and the Company's  Certificate  of
Incorporation  and By-Laws  limit the  monetary  liability  of  directors to the
Company and to its stockholders and provide for indemnification of the Company'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 the Company and, with respect to any criminal
action or proceeding,  actions that the  indemnitee  had no reasonable  cause to
believe were unlawful. The Company also has indemnification  agreements with its
directors and officers that provide for the maximum  indemnification  allowed by
law.

      The Company has an  insurance  policy  which  insures  the  directors  and
officers of the Company 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;
<PAGE>

                  (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 the  Registrant  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 the
Registrant'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 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 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 Act and will
be governed by the final adjudication of such issue.


<PAGE>


                                   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 Waltham, Commonwealth of Massachusetts,  on this 13th
day of January, 2000.

                                   THERMO ELECTRON CORPORATION


                                   By:  /s/ Richard F. Syron
                                        -----------------------------------
                                        Richard F. Syron
                                        Chief Executive Officer


                                POWER OF ATTORNEY

      Each  of  the  undersigned  Directors  and  Officers  of  Thermo  Electron
Corporation  hereby appoints Theo  Melas-Kyriazi,  Paul F. Kelleher,  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 and Chairman of the
/s/ Richard F. Syron          Board                         January 13, 2000
--------------------------
Richard F. Syron

/s/ Theo Melas-Kyriazi        Chief Financial Officer       January 13, 2000
--------------------------
Theo Melas-Kyriazi
<PAGE>

/s/ Paul F. Kelleher          Chief Accounting Officer      January 13, 2000
--------------------------
Paul F. Kelleher

/s/ George N. Hatsopoulos     Chairman Emeritus              January 13, 2000
--------------------------
George N. Hatsopoulos

/s/ John M. Albertine         Director                      January 13, 2000
--------------------------
John M. Albertine

/s/ Samuel W. Bodman          Director                      January 13, 2000
--------------------------
Samuel W. Bodman

/s/ Peter O. Crisp            Director                      January 13, 2000
--------------------------
Peter O. Crisp

/s/ Elias P. Gyftopoulos      Director                      January 13, 2000
--------------------------
Elias P. Gyftopoulos

/s/ John N. Hatsopoulos       Director                      January 13, 2000
--------------------------
John N. Hatsopoulos

/s/ Frank Jungers             Director                      January 13, 2000
--------------------------
Frank Jungers

/s/ Robert A. McCabe          Director                      January 13, 2000
--------------------------
Robert A. McCabe

/s/ Hutham S. Olayan          Director                      January 13, 2000
--------------------------
Hutham S. Olayan

/s/ Robert W. O'Leary         Director                      January 13, 2000
--------------------------
Robert W. O'Leary

/s/ Roger D. Wellington       Director                      January 13, 2000
--------------------------
Roger D. Wellington





<PAGE>


                                  EXHIBIT INDEX


Exhibit
Number            Description


     5.1  Opinion of Seth H. Hoogasian, Esq.

     5.2  Internal Revenue Service  Determination  Letter,  dated June 19, 1995,
          with respect to the qualification of the Coleman Research  Corporation
          401(k) Employee Stock Ownership Plan under Section 401 of the Internal
          Revenue Code.

     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 5.1



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




                                                      January 13, 2000

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

Re:   Registration Statement on Form S-8
      Relating to 1,310,000 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 1,310,000  shares of the Company's Common Stock,
$1.00 par value  per  share  (the  "Shares")  subject  to the  Coleman  Research
Corporation  401(k)  Employee  Stock  Ownership Plan (the "KSOP") and the Thermo
Electron Corporation  Employee Stock Purchase Plan (collectively,  the "Plans"),
as well as an  indeterminate  amount  of  related  interests  in the  KSOP  (the
"Interests").

      I or a member of my legal staff have  reviewed the  corporate  proceedings
taken by the Company  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 the Company
and have made all  investigations  of law and have  discussed with the Company'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. The Company is a  corporation  validly  existing and in corporate  good
standing under the laws of the State of Delaware.
<PAGE>

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

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

      I am also of the opinion that the respective  Plans confer valid Interests
upon the  participants  in such  Plans,  to the  extent  and upon the  terms and
conditions described in such Plans.

      I hereby  consent  to the filing of this  opinion  as  Exhibit  5.1 to the
Registration Statement.

                                          Very truly yours,


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


<PAGE>


                                                                    EXHIBIT 5.2


INTERNAL REVENUE SERVICE            DEPARTMENT OF THE TREASURY
DISTRICT DIRECTOR
P.O.  BOX 1055
ATLANTA, GA  30370

Date: June 19, 1995                 Employer Identification Number:
                                          59-2039476
Coleman Research Corporation        File Folder Number:
C/O Jack B. Levy, Esquire                 590023259
2222 Arlington Avenue, South        Person to Contact:
Birmingham, AL 35205                      HUGH SPIKLER
                                    Contact Telephone Number:
                                          (404) 331-4103
                                    Plan Name:
                                    COLEMAN RESEARCH CORPORATION 401(K)
                                    EMPLOYEE STOCK OWNERSHIP PLAN
                                    Plan Number: 001

Dear Applicant:

      We have made a favorable  determination  on your plan,  identified  above,
based on the  information  supplied.  Please keep this letter in your  permanent
records.

      Continued  qualification of the plan under its present form will depend on
its  effect  in  operation.  (See  section  1.401-1(b)  (3)  of the  Income  Tax
Regulations.) We will review the status of the plan in operation periodically.

      The  enclosed   document  explains  the  significance  of  this  favorable
determination  letter,  points out some  features  that may affect the qualified
status  of your  employee  retirement  plan,  and  provides  information  on the
reporting  requirements  for your  plan.  It also  describes  some  events  that
automatically nullify it. It is very important that you read the publication.

      This  letter  relates  only to the status of your plan under the  Internal
Revenue Code. It is not a determination regarding the effect of other federal or
local statutes.

      This  determination  letter is applicable for the amendment(s)  adopted on
10/28/94.

      This plan satisfies the requirements of Code section 4975 (e)(7).
<PAGE>

      This plan has been mandatorily disaggregated,  permissively aggregated, or
restructured to satisfy the nondiscrimination requirements.

      This plan satisfies the nondiscrimination in amount requirement of section
1.401 (a)(4) - 1 (b) (2) of the regulations on the basis of a design-based  safe
harbor described in the regulations.

     This letter is issued under Rev.  Proc.  93-39 and considers the amendments
required by the Tax Reform Act of 1986  except as  otherwise  specified  in this
letter.

      This   plan   satisfies   the   nondiscriminatory   current   availability
requirements of section 1.401 (a) (4)-4 (b) of the  regulations  with respect to
those  benefits,  rights,  and  features  that are  currently  available  to all
employees in the plan's  coverage group.  For this purpose,  the plan's coverage
group consists of those employees  treated as currently  benefiting for purposes
of demonstrating  that the plan satisfies the minimum  coverage  requirements of
section 410 (b) of the Code.

     This  letter  may not be  relied  upon with  respect  to  whether  the plan
satisfies  the  qualification  requirements  as  amended  by the  Uruguay  Round
Agreements Act, Pub. L. 103-465.

      We have sent a copy of this letter to your  representative as indicated in
the power of attorney.

      If you have questions  concerning  this matter,  please contact the person
whose name and telephone number are shown above.

                                        Sincerely yours,


                                        /s/  Nelson A. Brooke
                                        ----------------------------------
                                             Nelson A. Brooke
                                             District Director

Enclosures:
Publication 794
Reporting and Disclosure Guide
for Employee Benefit Plans




<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 reports  dated
February 16, 1999  (except with respect to the matters  discussed in Note 19, as
to which the date is March 1, 1999),  included in Thermo Electron  Corporation's
Annual  Report on Form  10-K for the year  ended  January  2,  1999,  and to all
references to our Firm included in this registration statement.


                                               Arthur Andersen LLP



Boston, Massachusetts
January 6, 2000
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 27735}]
{"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": "333-94627", "film-number": "507080"}, "business-address": {"street1": "81 WYMAN ST", "street2": "P O BOX 9046", "city": "WALTHAM", "state": "MA", "zip": "02454", "phone": "7816221000"}}
As filed with the Securities and Exchange Commission on January 13, 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)

        COLEMAN RESEARCH CORPORATION 401(K) EMPLOYEE STOCK OWNERSHIP PLAN

            THERMO ELECTRON CORPORATION EMPLOYEE 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

 Title of                                       Proposed
securities         Amount       Proposed        Maximum              Amount of
  to be             to be        Maximum        Aggregate          Registration
registered        registered    Offering        Offering                Fee
                                Price Per         Price
                                 Share
Common Stock,
 $1.00 par         1,310,000     $14.53125     $19,035,937.50          $5,026
 value per          shares          (2)              (2)
  share               (1)

     In addition, pursuant to Rule 416(c) under the Securities Act of 1933, this
Registration Statement also covers an indeterminate number of interests issuable
in  connection  with the Coleman  Research  Corporation  401(k)  Employee  Stock
Ownership Plan and an indeterminate  number of shares of the Registrant's Common
Stock as may be issuable  in  connection  with  adjustments  under the  employee
benefit plans described  herein to reflect  certain changes in the  Registrant's
capital structure, including stock dividends or stock splits.

(1)   Of the shares registered hereunder,  560,000 shares are issuable under the
      Coleman  Research  Corporation  401(k)  Employee Stock Ownership Plan, and
      750,000 of the shares  registered  hereunder are issuable under the Thermo
      Electron Corporation Employee Stock Purchase Plan.

(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
      1,310,000  shares and (2) the  average  of the high and low sales  prices,
      $14.75 and $14.3125, respectively, of the Registrant's Common Stock on the
      New York Stock Exchange on January 7, 2000 as reported in the consolidated
      transaction reporting system.
EXPLANATORY NOTE

      This Registration  Statement is filed pursuant to General Instruction E of
Form S-8 in order to register  additional  securities of the same class as other
securities for which a registration  statement  relating to the Coleman Research
Corporation  401(k)  Employee Stock  Ownership Plan (the "Coleman Plan") and the
Thermo  Electron  Corporation  Employee  Stock  Purchase  Plan (the  "ESPP")  is
effective.

     On January 10, 1997, the Company filed a registration statement on Form S-8
(Reg. No.  333-19535) to register an aggregate of 250,000 shares of Common Stock
reserved for issuance under the Coleman Plan. The addition of this  Registration
Statement  brings the total number of shares  registered  for issuance under the
Coleman Plan to 810,000. In addition,  on November 16, 1990, the Company filed a
registration  statement on Form S-8 (Reg. No. 33-37865) to register an aggregate
of 400,000  shares of Common Stock  reserved for  issuance  under the ESPP.  The
addition of this Registration  Statement,  together with the effect of 3:2 stock
splits in 1993,  1995 and 1996 brings the total  number of shares that have been
registered  for  issuance  under  the ESPP to  2,100,000.  The  contents  of the
previously filed  registration  statements  relating to the Coleman Plan and the
ESPP are  incorporated  herein by  reference  except  for the items that are set
forth below.  Pursuant to Instruction E, this  Registration  Statement  contains
such  information  required  by Form S-8 that is not  otherwise  included in the
previous registration statement.

                                     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  respective  plans  pursuant  to  Rule
428(b)(1) under the Securities Act of 1933, as amended (the  "Securities  Act").
As used in this  Registration  Statement,  the terms  "Registrant"  or "Company"
refer to Thermo Electron Corporation.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

      The Registrant 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 (the  "Exchange  Act"),  and in accordance  therewith  files reports,
proxy  statements  and  other  information  with  the  Securities  and  Exchange
Commission (the "Commission").  The following documents,  which are on file with
the Commission, are incorporated in this Registration Statement by reference:

            (a)   The  Company's  Annual Report on Form 10-K for the fiscal year
                  ended January 2, 1999.

            (b)   The  Company's  Current  Report  on Form  8-K  filed  with the
                  Commission on January 8, 1999.
(c)   The  Company's  Current  Report  on Form  8-K  filed  with the
                  Commission on March 9, 1999.

            (d)   The  Company's  Current  Report  on Form  8-K  filed  with the
                  Commission on March 15, 1999.

            (e)   The  Company's  Quarterly  Report on Form 10-Q for the quarter
                  ended April 3, 1999.

            (f)   The  Company's  Current  Report  on Form  8-K  filed  with the
                  Commission on May 25, 1999.

            (g)   The  Company's  Quarterly  Report on Form 10-Q for the quarter
                  ended July 3, 1999.

            (h)   The  Company's  Quarterly  Report on Form 10-Q for the quarter
                  ended October 2, 1999.

            (i)   The  Company's  Current  Report  on Form  8-K  filed  with the
                  Commission on December 21, 1999.

            (j)   The  description of the Common Stock which is contained in the
                  Company'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 the Company 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 the Company.  Mr.  Hoogasian is a
full-time employee of the Company, is an officer of the Company, and owns or has
the right to acquire  348,944  shares of Common Stock and 162,177  shares of the
Company's subsidiaries.
Item 6.  Indemnification of Directors and Officers.

      The Delaware  General  Corporation  Law and the Company's  Certificate  of
Incorporation  and By-Laws  limit the  monetary  liability  of  directors to the
Company and to its stockholders and provide for indemnification of the Company'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 the Company and, with respect to any criminal
action or proceeding,  actions that the  indemnitee  had no reasonable  cause to
believe were unlawful. The Company also has indemnification  agreements with its
directors and officers that provide for the maximum  indemnification  allowed by
law.

      The Company has an  insurance  policy  which  insures  the  directors  and
officers of the Company 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 the  Registrant  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 the
Registrant'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 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 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 Act and will
be governed by the final adjudication of such issue.
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 Waltham, Commonwealth of Massachusetts,  on this 13th
day of January, 2000.

                                   THERMO ELECTRON CORPORATION

                                   By:  /s/ Richard F. Syron
                                        -----------------------------------
                                        Richard F. Syron
                                        Chief Executive Officer

                                POWER OF ATTORNEY

      Each  of  the  undersigned  Directors  and  Officers  of  Thermo  Electron
Corporation  hereby appoints Theo  Melas-Kyriazi,  Paul F. Kelleher,  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 and Chairman of the
/s/ Richard F. Syron          Board                         January 13, 2000
--------------------------
Richard F. Syron

/s/ Theo Melas-Kyriazi        Chief Financial Officer       January 13, 2000
--------------------------
Theo Melas-Kyriazi
/s/ Paul F. Kelleher          Chief Accounting Officer      January 13, 2000
--------------------------
Paul F. Kelleher

/s/ George N. Hatsopoulos     Chairman Emeritus              January 13, 2000
--------------------------
George N. Hatsopoulos

/s/ John M. Albertine         Director                      January 13, 2000
--------------------------
John M. Albertine

/s/ Samuel W. Bodman          Director                      January 13, 2000
--------------------------
Samuel W. Bodman

/s/ Peter O. Crisp            Director                      January 13, 2000
--------------------------
Peter O. Crisp

/s/ Elias P. Gyftopoulos      Director                      January 13, 2000
--------------------------
Elias P. Gyftopoulos

/s/ John N. Hatsopoulos       Director                      January 13, 2000
--------------------------
John N. Hatsopoulos

/s/ Frank Jungers             Director                      January 13, 2000
--------------------------
Frank Jungers

/s/ Robert A. McCabe          Director                      January 13, 2000
--------------------------
Robert A. McCabe

/s/ Hutham S. Olayan          Director                      January 13, 2000
--------------------------
Hutham S. Olayan

/s/ Robert W. O'Leary         Director                      January 13, 2000
--------------------------
Robert W. O'Leary

/s/ Roger D. Wellington       Director                      January 13, 2000
--------------------------
Roger D. Wellington
EXHIBIT INDEX

Exhibit
Number            Description

     5.1  Opinion of Seth H. Hoogasian, Esq.

     5.2  Internal Revenue Service  Determination  Letter,  dated June 19, 1995,
          with respect to the qualification of the Coleman Research  Corporation
          401(k) Employee Stock Ownership Plan under Section 401 of the Internal
          Revenue Code.

     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 5.1

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

                                                      January 13, 2000

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

Re:   Registration Statement on Form S-8
      Relating to 1,310,000 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 1,310,000  shares of the Company's Common Stock,
$1.00 par value  per  share  (the  "Shares")  subject  to the  Coleman  Research
Corporation  401(k)  Employee  Stock  Ownership Plan (the "KSOP") and the Thermo
Electron Corporation  Employee Stock Purchase Plan (collectively,  the "Plans"),
as well as an  indeterminate  amount  of  related  interests  in the  KSOP  (the
"Interests").

      I or a member of my legal staff have  reviewed the  corporate  proceedings
taken by the Company  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 the Company
and have made all  investigations  of law and have  discussed with the Company'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. The Company 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 the Company.

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

      I am also of the opinion that the respective  Plans confer valid Interests
upon the  participants  in such  Plans,  to the  extent  and upon the  terms and
conditions described in such Plans.

      I hereby  consent  to the filing of this  opinion  as  Exhibit  5.1 to the
Registration Statement.

                                          Very truly yours,

                                        /s/  Seth H. Hoogasian
                                        ----------------------------------
                                             Seth H. Hoogasian
                                             General Counsel
EXHIBIT 5.2

INTERNAL REVENUE SERVICE            DEPARTMENT OF THE TREASURY
DISTRICT DIRECTOR
P.O.  BOX 1055
ATLANTA, GA  30370

Date: June 19, 1995                 Employer Identification Number:
                                          59-2039476
Coleman Research Corporation        File Folder Number:
C/O Jack B. Levy, Esquire                 590023259
2222 Arlington Avenue, South        Person to Contact:
Birmingham, AL 35205                      HUGH SPIKLER
                                    Contact Telephone Number:
                                          (404) 331-4103
                                    Plan Name:
                                    COLEMAN RESEARCH CORPORATION 401(K)
                                    EMPLOYEE STOCK OWNERSHIP PLAN
                                    Plan Number: 001

Dear Applicant:

      We have made a favorable  determination  on your plan,  identified  above,
based on the  information  supplied.  Please keep this letter in your  permanent
records.

      Continued  qualification of the plan under its present form will depend on
its  effect  in  operation.  (See  section  1.401-1(b)  (3)  of the  Income  Tax
Regulations.) We will review the status of the plan in operation periodically.

      The  enclosed   document  explains  the  significance  of  this  favorable
determination  letter,  points out some  features  that may affect the qualified
status  of your  employee  retirement  plan,  and  provides  information  on the
reporting  requirements  for your  plan.  It also  describes  some  events  that
automatically nullify it. It is very important that you read the publication.

      This  letter  relates  only to the status of your plan under the  Internal
Revenue Code. It is not a determination regarding the effect of other federal or
local statutes.

      This  determination  letter is applicable for the amendment(s)  adopted on
10/28/94.

      This plan satisfies the requirements of Code section 4975 (e)(7).
This plan has been mandatorily disaggregated,  permissively aggregated, or
restructured to satisfy the nondiscrimination requirements.

      This plan satisfies the nondiscrimination in amount requirement of section
1.401 (a)(4) - 1 (b) (2) of the regulations on the basis of a design-based  safe
harbor described in the regulations.

     This letter is issued under Rev.  Proc.  93-39 and considers the amendments
required by the Tax Reform Act of 1986  except as  otherwise  specified  in this
letter.

      This   plan   satisfies   the   nondiscriminatory   current   availability
requirements of section 1.401 (a) (4)-4 (b) of the  regulations  with respect to
those  benefits,  rights,  and  features  that are  currently  available  to all
employees in the plan's  coverage group.  For this purpose,  the plan's coverage
group consists of those employees  treated as currently  benefiting for purposes
of demonstrating  that the plan satisfies the minimum  coverage  requirements of
section 410 (b) of the Code.

     This  letter  may not be  relied  upon with  respect  to  whether  the plan
satisfies  the  qualification  requirements  as  amended  by the  Uruguay  Round
Agreements Act, Pub. L. 103-465.

      We have sent a copy of this letter to your  representative as indicated in
the power of attorney.

      If you have questions  concerning  this matter,  please contact the person
whose name and telephone number are shown above.

                                        Sincerely yours,

                                        /s/  Nelson A. Brooke
                                        ----------------------------------
                                             Nelson A. Brooke
                                             District Director

Enclosures:
Publication 794
Reporting and Disclosure Guide
for Employee Benefit Plans
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 reports  dated
February 16, 1999  (except with respect to the matters  discussed in Note 19, as
to which the date is March 1, 1999),  included in Thermo Electron  Corporation's
Annual  Report on Form  10-K for the year  ended  January  2,  1999,  and to all
references to our Firm included in this registration statement.

                                               Arthur Andersen LLP

Boston, Massachusetts
January 6, 2000