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 Quarterly Report on Form 10-Q for the quarterly period
          ended June 29, 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 for the periods covered by the Report.


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


Dated: August 11, 2003