Cabot Microelectronics Announces Global Price Increase on Selected Products.

AURORA, lll. -- Cabot Microelectronics Corporation (Nasdaq:CCMP), the world's leading supplier of chemical mechanical planarization (CMP) polishing slurries to the semiconductor industry, today announced a global price increase for the Semi-Sperse[R] and Cab-O-Sperse[R] product lines used for interlayer dielectrics and general-purpose oxide polishing applications. The new prices will be effective for orders to be delivered on or after December 1, 2006.

Stephen Smith, Vice President of Marketing for Cabot Microelectronics, stated, "These products have been helping customers meet their polishing needs since their introduction in the early 1990's. For more than a decade, Cabot Microelectronics has continually invested in improving these products to meet increasing performance demands as semiconductor technology has advanced, and our customers have benefited from these improvements. We are now increasing our prices for the first time since these products were introduced so that we may continue to provide the level of service our customers and we expect. We are committed to helping our customers meet their needs today and in the future, so we plan to continue to invest in further improving these products as well as introducing new and higher performing products for similar applications."

ABOUT CABOT MICROELECTRONICS CORPORATION

Cabot Microelectronics Corporation, headquartered in Aurora, Illinois, is the world's leading supplier of CMP slurries used in semiconductor and data storage manufacturing. 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. Since becoming an independent public company in 2000, the company has grown to nearly 750 employees who work at research and development labs, sales and business offices, manufacturing facilities and customer service centers in China, France, Germany, Japan, Singapore, South Korea, Taiwan, the United Kingdom and the United States. The company's vision is to become the world leader in shaping, enabling and enhancing the performance of surfaces, and thus looks beyond its core CMP business in the semiconductor industry. For more information about Cabot Microelectronics Corporation, visit www.cabotcmp.com or contact Barbara Ven Horst, Director of Investor Relations at [phone].