CCMP CMC Materials Inc

In celebration of its 10th anniversary as a public company, Cabot Microelectronics Corporation (Nasdaq:CCMP), the world's leading supplier of chemical mechanical planarization (CMP) polishing slurries and growing CMP pad supplier to the semiconductor industry, announced today that it will host its 2010 Investor Day on Thursday, June 3, 2010, at the NASDAQ MarketSite in Times Square, from 10:30 a.m. to 3:00 p.m. Eastern Time. During the event, Cabot Microelectronics' Chairman and CEO, William Noglows, and members of the company's leadership team will discuss the company's business and strategy. Following the Investor Day event, the company will host the NASDAQ market close ceremony.

Forward looking information may be discussed during the Investor Day event and will be webcast and archived on the Company's website for 30 days. Interested parties may listen to the webcast and view the accompanying slide presentations by visiting the Investor Relations page of the company's website, www.cabotcmp.com. For additional information or to register for the event, please contact Amy Ford, Director of Investor Relations at (630) 499-2600. All event attendees must pre-register.

ABOUT CABOT MICROELECTRONICS CORPORATION

Cabot Microelectronics Corporation, headquartered in Aurora, Illinois, is the world's leading supplier of CMP polishing slurries and growing CMP pad supplier to the semiconductor industry. The company's products play a critical role in the production of advanced semiconductor devices, enabling the manufacture of smaller, faster and more complex devices by its customers. The company's mission is to create value by developing reliable and innovative solutions, through close customer collaboration, that solve today's challenges and help enable tomorrow's technology. Since becoming an independent public company in 2000, the company has grown to approximately 900 employees on a global basis. For more information about Cabot Microelectronics Corporation, visit www.cabotcmp.com or contact Amy Ford, Director of Investor Relations at (630) 499-2600.

The Cabot Microelectronics Corporation logo is available at http://www.globenewswire.com/newsroom/prs/?pkgid=6902

CONTACT:  Cabot Microelectronics Corporation 
          (630) 499-2600