EXHIBIT 32.1


                            CERTIFICATION PURSUANT TO
            SECTION 1350, CHAPTER 63 OF TITLE 18, UNITED STATES CODE,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


Pursuant to Section 1350, Chapter 63 of Title 18, United States Code, as adopted
pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, the undersigned, as
President and Chief Executive Officer of BTU International, Inc. (the
"Company"), does hereby certify that to his knowledge:

     1)   the Company's Annual Report on Form 10-K for the year ended December
          31, 2003 (the "Report") fully complies with the requirements of
          Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

     2)   the information contained in the Report fairly presents, in all
          material respects, the financial condition and results of operations
          of the Company.



                                    /s/ Mark R. Rosenzweig
                                    ----------------------------------------
                                    Mark R. Rosenzweig
                                    President and Chief Executive Officer



Dated: March 30, 2004