MINNEAPOLIS & BOSTON--(BUSINESS WIRE)--Aug. 3, 2005--

New CEO Argov Says Merger Will Nearly Double Company Size

Entegris, Inc. (NASDAQ:ENTG), and Mykrolis Corporation (NYSE:MYK) today announced that their respective stockholders approved the proposed merger between the two companies at stockholder meetings conducted today. Approximately 81 percent of the outstanding Entegris shares were represented at the meeting, and approximately 99 percent of the shares voted on the merger proposal were cast in favor. Mykrolis shareholders showed similar support with approximately 99 percent of the shares voted on the merger proposal cast in favor of the merger.

According to the terms of the merger agreement, each share of Mykrolis common stock will be exchanged for 1.39 shares of Entegris common stock on the closing of the merger, which is expected to occur on August 6, 2005.

Gideon Argov, the current Mykrolis CEO, will become the CEO of the combined company. According to Argov, the merger creates the largest global materials integrity management company today, with combined sales of approximately $650 million for the trailing twelve months. The company will focus on products and services that purify, protect, and transport critical materials used in semiconductor and other high technology industries.

"This merger combines two strong, successful companies into one of the most recognized and respected suppliers to the global semiconductor industry today," said Argov. "We are excited to launch the new Entegris so that the opportunities created by this merger can be realized for customers, partners, shareholders and employees."

The combined company will be named Entegris, although the Mykrolis brand will be retained for certain products. This plays on the strengths of both companies in serving multiple markets worldwide.

Current Entegris CEO Jim Dauwalter, will become the non-executive chairman of the board for Entegris. "Each company has successfully established very significant market presence, and the union of our two companies will make Entegris even stronger, from Japan and Asia Pacific, to the United States and Europe," said Dauwalter. "I am confident that Gideon, his leadership team and our dedicated employees will take Entegris to an exciting, growth-oriented future."

ABOUT THE NEW ENTEGRIS

Upon the completion of the merger, Entegris will be the global leader in materials integrity management - purifying, protecting and transporting critical materials used in high technology products, processes and services. Entegris provides products and services used in semiconductor and other high-technology industries. Entegris is ISO 9001 certified and has manufacturing, service or research facilities in the United States, China, France, Germany, Japan, Malaysia, Singapore, South Korea and Taiwan. Additional information can be found at www.entegris.com.

CONTACT: Mykrolis Corporation
Investor Relations and Corporate Communications:
Steve Cantor, 978-436-6750
Investor_relations@mykrolis.com
or
Entegris, Inc.


Public Relations:
Bill Paterson, 952-556-4155
Bill_paterson@entegris.com
or
Investor Relations:
Heide Erickson, 952-556-8051


Heide_Erickson@entegris.com

SOURCE: Entegris, Inc.