CCMP CMC Materials Inc

Cabot Microelectronics Corporation (Nasdaq:CCMP), the leading supplier of chemical mechanical planarization (CMP) polishing slurries to the semiconductor industry, announced today that it will release financial results for its third quarter of fiscal 2005, which ended June 30, 2005, on Thursday, July 28. The press release, which will be issued prior to market open and available in the Investor Relations section of the company's website, www.cabotcmp.com, will be followed by a conference call at 10:00 a.m. Eastern time, 9:00 a.m. Central time. William Noglows, Cabot Microelectronics' Chairman, President and CEO, will host the call. The conference call will be available to all interested parties via webcast from its website, www.cabotcmp.com, or by phone at (800) 893-3008. Callers outside the U.S. can dial (706) 634-5531. For those who cannot listen to the live broadcast, a replay will be available through August 18, 2005, by calling (800) 642-1687 or (706) 645-9291, and using access code 4381279, or via webcast at www.cabotcmp.com. A transcript of the formal comments made during the conference call will be available in the Investor Relations section of the company's website, www.cabotcmp.com. About Cabot Microelectronics Cabot Microelectronics Corporation, headquartered in Aurora, Illinois, is the leading supplier of CMP slurries for polishing various materials used in semiconductor manufacturing processes. The company's products play a critical role in the production of the most advanced semiconductor devices, enabling the manufacture of smaller, faster and more complex devices by its customers. For more information about Cabot Microelectronics Corporation, visit www.cabotcmp.com or contact Investor Relations at (630) 499-2600. Safe Harbor Statement This news release may include statements that constitute "forward-looking statements" within the meaning of federal securities regulations. These forward-looking statements include statements related to future sales and operating results, company and industry growth and trends, growth of the markets in which the company participates, international events, product performance, new product introductions, development of new products and technologies, and the construction of new facilities by Cabot Microelectronics. These forward-looking statements involve a number of risks, uncertainties, and other factors, including those described from time to time in Cabot Microelectronics' filings with the Securities and Exchange Commission (SEC), that could cause actual results to differ materially from those described by these forward-looking statements. In particular, see "Risks Relating to Our Business" in Management's Discussion and Analysis in our quarterly report on Form 10-Q for the quarter ended March 31, 2005, and our Annual Report on Form 10-K for the fiscal year ended September 30, 2004, both filed with the SEC. Cabot Microelectronics Corporation assumes no obligation to update this forward-looking information.