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                                                                    EXHIBIT 23.1


            Consent of Independent Registered Public Accounting Firm

         We consent to the incorporation by reference in the Registration
Statement (Form S-3 No. 333-85214) of Axcelis Technologies, Inc. and in the
related Prospectus, the Registration Statements (Form S-8 No. 333-49726)
pertaining to the Axcelis Technologies, Inc. Employee Stock Purchase Plan and
the Registration Statements (Forms S-8 No. 333-49768 and 333-120356)
pertaining to the Axcelis Technologies, Inc. 2000 Stock Plan, of our reports
dated March 11, 2005, with respect to the consolidated financial statements
and schedule of Axcelis Technologies, Inc., Axcelis Technologies, Inc.
management's assessment of the effectiveness of internal control over
financial reporting, and the effectiveness of internal control over financial
reporting of Axcelis Technologies, Inc., included in this Annual Report (Form
10-K) for the year ended December 31, 2004.

                                                /s/ Ernst & Young LLP

Boston, Massachusetts
March 11, 2005