Exhibit 99.1

PRESS RELEASE
FOR IMMEDIATE RELEASE

                                              CONTACT:
                                              David H. Li
                                              Director of Investor Relations
                                              Cabot Microelectronics Corporation
                                              630/499-2600


               CABOT MICROELECTRONICS CORPORATION FORMS STRATEGIC
                     ALLIANCE WITH NANOPRODUCTS CORPORATION

AURORA, Illinois - July 1, 2004 - Cabot Microelectronics Corporation (NASDAQ:
CCMP), the leading supplier of chemical mechanical planarization (CMP) polishing
slurries to the semiconductor industry, announced today that it has entered into
a strategic alliance with NanoProducts Corporation, a privately-held technology
leader in nanoscale particles and related nanotechnology products. As part of
the alliance, Cabot Microelectronics and NanoProducts will collaborate to
develop nanoscale powders and particles for use in fine finish polishing
applications, including CMP slurries. In addition, Cabot Microelectronics has
obtained a minority equity stake in NanoProducts for an investment of $3.75
million in the company.

The alliance significantly strengthens a joint development relationship between
the parties that has been ongoing since 2002, and provides that NanoProducts
will work exclusively with Cabot Microelectronics in developing its technology
in the area of CMP. The agreement has an initial term of three years, and is
renewable.

"We believe that engineered nanoparticles and powders, which are distinctive in
their ability to be customized to deliver unique performance attributes, will
play a significant role in our next generation products," stated William P.
Noglows, Chairman and Chief Executive Officer of Cabot Microelectronics. "We are
delighted to launch a strategic alliance with NanoProducts that optimizes the
combination of NanoProducts' innovative technology, and Cabot Microelectronics'
world class technology, resources and infrastructure to deliver significant
additional value to our customers and provide us with a competitive edge. Our
strategic investment in NanoProducts affords us the opportunity to partner with
a company that has developed unique, compelling technology and intellectual
property in nanomaterials that can assist us in meeting the technology
challenges and quality requirements of the semiconductor industry, furthering
our leadership position in CMP slurries, and providing unique abrasive
capabilities for other fine finish polishing applications."



"We are thrilled about our strategic alliance with Cabot Microelectronics,"
stated Tapesh Yadav, Ph.D., NanoProducts' President and Chief Executive Officer.
"Cabot Microelectronics' leadership position in CMP slurries, and preeminent
research and development resources and technology infrastructure, combined with
our unique nanomaterials technology, should provide an exceptional platform from
which to develop a pipeline of innovative solutions for the CMP industry."

ABOUT NANOTECHNOLOGY

Nanotechnology is the science of fabricating materials with atomic or molecular
scale precision. Materials with minimum feature sizes of less than 100
nanometers (nm) are considered to be products of nanotechnology. A nanometer is
one billionth of a meter and is the unit of length that is generally most
appropriate for describing the size of single molecules. Nanotechnology can be
used to manufacture tailor-made products with unique performance attributes.

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 Mr. David H. Li, Director of Investor Relations at
630.499.2600.

ABOUT NANOPRODUCTS

NanoProducts Corporation, based in Longmont, Colorado, serves customers in the
emerging nanotechnology marketplace with a unique portfolio of products and
solutions. NanoProducts uses a platform of patented technologies and proprietary
know-how to create and supply nanomaterials with unique performance attributes.
The company's products are currently being qualified and adopted by
innovation-driven market leaders in coatings, additives for polymers and
plastics, personal care, catalysts, pigments, health care, electronics,
information management and optical products. The company owns over 40 granted
patents and an additional 40 pending patents on various nanotechnologies. For
more information about NanoProducts, visit www.nanoproducts.com or contact Dr.
Elizabeth Dohe, Director of Customer Services at 970.535.0629 Ext 240.



SAFE HARBOR STATEMENT

The statements contained in this news release include statements that constitute
"forward-looking statements" within the meaning of federal securities
regulations. These forward-looking statements include statements related to
future sales, future benefits of the alliance, company and industry growth and
trends, the future role of nanoparticles in company research and development and
CMP products, new product introductions and development of new products and
technologies 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 the 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,
2004, and our Annual Report on Form 10-K for the fiscal year ended September 30,
2003, filed with the SEC. Cabot Microelectronics Corporation assumes no
obligation to update this forward-looking information.