EXHIBIT 99.1

                            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, 2002 (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 31, 2003