1 Exhibit 23.1 Consent of Independent Auditors We consent to the reference to our firm under the captions "Summary Historical Financial Data," "Selected Historical Combined Financial Data," and "Experts," and to the use of our report dated May 3, 2000, in Amendment No. 2 to the Registration Statement (Form S-1 No. 333-36330) and related Prospectus of Axcelis Technologies, Inc. for the registration of shares of its common stock. Cleveland, Ohio June 16, 2000 /s/ Ernst and Young LLP