May 23, 2005 – Axcelis Technologies Inc. has announced that the company’s board of directors has elected president and CEO Mary Puma, 47, to the position of chairman of the board. Puma, whose new title is chairman and CEO, succeeds Stephen Hardis, who has been named Axcelis’ lead director.

“Mary has demonstrated extraordinary leadership ability since becoming chief executive officer of Axcelis in 2002,” said Hardis. “Her success in improving Axcelis’ operational efficiency while driving continued innovation in its technology has positioned the company well for future success. We look forward to her continued contributions as chairman.”

“I am honored to accept the role of chairman of Axcelis’ board of directors,” said Puma. “I am confident that Axcelis is very well positioned for the future.”

Puma played an instrumental role in Axcelis’ spin out from Eaton Corp. in 2000, when she was named the company’s president and COO. She joined Eaton in 1996 as the GM of its commercial controls division. In 1998, she became VP of Eaton’s implant business. She was promoted to VP of the semiconductor operation in 1999. Prior to joining Eaton, Puma spent 15 years in various marketing and general management positions at five different General Electric business units.

Puma holds a masters degree in management from the MIT Sloan School and a bachelors degree in economics, Phi Beta Kappa, from Tufts University. She is a member of the boards at Nordson Corp., Semiconductor Equipment and Materials International (SEMI), and the North Shore United Way.