As filed with the Securities and Exchange Commission on March 2, 2006.
                           Registration No. 333-33062
            --------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION

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

                         POST-EFFECTIVE AMENDMENT NO. 1
                                       ON
                                    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 ELECTRON CORPORATION - THERMORETEC CORPORATION
                         NONQUALIFIED STOCK OPTION PLAN
             THERMO ELECTRON CORPORATION DIRECTORS STOCK OPTION PLAN
                              (THERMORETEC SHARES)
          THERMO TERRATECH INC. - THERMORETEC CORPORATION NONQUALIFIED
                               STOCK OPTION PLAN
         THERMO TERRATECH INC. DIRECTORS STOCK OPTION PLAN (THERMORETEC
                                    SHARES)
               THERMORETEC CORPORATION DIRECTORS STOCK OPTION PLAN
                  RETEC - THERMORETEC CORPORATION EXCHANGE PLAN
                  THERMORETEC CORPORATION EQUITY INCENTIVE PLAN
             THERMORETEC CORPORATION EMPLOYEES EQUITY INCENTIVE PLAN
                            (Full Title of the Plan)

                          Seth H. Hoogasian, Secretary
                           Thermo Electron Corporation
                                 81 Wyman Street
                        Waltham, Massachusetts 02454-9046

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




                          Deregistration of Securities

     This  Post-Effective  Amendment  No.  1 on  Form  S-8 to  the  Registration
Statement  on Form  S-8  (Registration  No.  333-33062)  is  being  filed by the
Registrant to remove from  registration any of the securities that remain unsold
thereunder  as of the  date of  filing  of this  post-effective  amendment.  The
securities  were  previously  registered  for sale  under  the  Thermo  Electron
Corporation - Thermoretec Corporation Nonqualified Stock Option Plan, the Thermo
Electron  Corporation  Directors  Stock Option Plan  (Thermoretec  shares),  the
Thermo Terratech Inc. - Thermoretec Corporation  Nonqualified Stock Option Plan,
the Thermo Terratech Inc. Directors Stock Option Plan (Thermoretec  shares), the
Thermoretec  Corporation  Directors  Stock Option Plan,  the Retec - Thermoretec
Corporation  Exchange Plan, the Thermoretec  Corporation  Equity Incentive Plan,
and the Thermoretec  Corporation  Employees Equity Incentive Plan (collectively,
the "Plans").  The deregistered  securities  represent shares subject to options
granted under the Plans that expired, were canceled or terminated without having
been  exercised.  As such, the Registrant  hereby removes such  securities  from
registration and the registration is hereby terminated.




                                   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  Post-Effective
Amendment on Form S-8 to be signed on its behalf by the  undersigned,  thereunto
duly authorized, in the City of Waltham, Commonwealth of Massachusetts,  on this
28th day of February, 2006.

                                    THERMO ELECTRON CORPORATION


                                    By:    /s/ Marijn E. Dekkers
                                           -------------------------- ----------
                                           Marijn E. Dekkers
                                    Its:   President and Chief Executive Officer

     Pursuant  to  the   requirements  of  the  Securities  Act  of  1933,  this
Post-Effective Amendment on Form S-8 has been signed by the following persons in
the capacities and on the dates indicated.



                                                                                                          

               Signature                                                  Title                                       Date
               ---------                                                  -----                                       ----
                                                            President, Chief Executive
/s/ Marijn E. Dekkers                                       Officer and Director (Principal
- ------------------------------------------------------      Executive Officer)                                  February 28, 2006
Marijn E. Dekkers

/s/ Jim P. Manzi                                            Chairman of the Board and
- ------------------------------------------------------      Director                                            February 28, 2006
Jim P. Manzi
                                                            Vice President and Chief
/s/ Peter M. Wilver                                         Financial Officer (Principal
- ------------------------------------------------------      Financial Officer)                                  February 28, 2006
Peter M. Wilver
                                                            Corporate Controller and Chief
/s/ Peter E. Hornstra                                       Accounting Officer (Principal
- ------------------------------------------------------      Accounting Officer)                                 February 28, 2006
Peter E. Hornstra

/s/ John L. LaMattina
- ------------------------------------------------------      Director                                            February 28, 2006
John L. LaMattina

/s/ Peter J. Manning
- ------------------------------------------------------      Director                                            February 28, 2006
Peter J. Manning

/s/ Robert A. McCabe
- ------------------------------------------------------      Director                                            February 28, 2006
Robert A. McCabe




/s/ Robert W. O'Leary
- ------------------------------------------------------      Director                                            February 28, 2006
Robert W. O'Leary

/s/ Michael E. Porter
- ------------------------------------------------------      Director                                            February 28, 2006
Michael E. Porter

/s/ Elaine S. Ullian
- ------------------------------------------------------      Director                                            February 28, 2006
Elaine S. Ullian