MKS Preliminary Results Exceed Expectations

Waterloo, ON — April 18, 2005: MKS Inc. (TSX:MKX) today announced that Tundra Semiconductor Corporation (TSX:TUN), a leader in System Interconnect, has standardized on MKS’s enterprise software change and configuration management solution, the MKS Integrity Suite™, to streamline design processes, and to provide greater control, visibility, and code reuse across its geographically distributed research and development operations.

Based on preliminary financial data for its fourth quarter of fiscal 2005, MKS anticipates total revenue to be between $12.2 million and $12.5 million, the highest quarterly revenue ever reported by the Company. License revenue is expected to be in the range of $7.0 million to $7.3million for the quarter. Net income for the fourth quarter of fiscal 2005 is expected to be in the range of $1.4 million to $1.7 million, or $0.03 to $0.04 per share. The Company has not yet determined whether there will be any accounting for income taxes in the fourth quarter, although there are sufficient losses carried forward to shelter the liability for any cash taxes arising in fiscal 2005. Cash balances at April 30, 2005 are expected to exceed $7.5 million, up from $4.9 million at January 30, 2005.

"We were delighted to be able to finish fiscal 2005 with the best revenue and profit quarter in our history. These results reflect outstanding performance across the Company, led by strong SCM licensing," said Philip Deck, MKS chairman and CEO. "Our performance in the areas of new licensing, competitive wins and our long term outlook continues to improve, although we view the fourth quarter revenue performance to be somewhat above the long term trend of revenue growth."

MKS will offer full year fiscal guidance with the release of its final audited results on June 1, 2005.

Conference Call Details for June 1, 2005
The Company will hold a conference call at 5:00 p.m. ET after close of markets on June 1, 2005 to discuss its fourth quarter and year-end performance and results. Interested parties may access the call by dialing 888-633-8408 or 416-641-6675. A recording of the call will be available for one (1) week from June 1, 2005 to June 8, 2005 and may be accessed by dialing 800 558 5253, reservation or 1-416-626-4100, reservation #21245926.

About MKS
MKS is the preeminent provider of enterprise technology management solutions for the global 1000. MKS’s solution spans the application lifecycle from requirements management, through application development, to server deployment providing customers with greater visibility over software development activities, enhanced development productivity and improved IT controls for regulatory compliance. MKS solutions are distinguished by their ease of implementation and low total cost of ownership. Founded in 1984, MKS serves more than 10,000 customers in countries across the world. Whether through deployment of MKS’s enterprise solutions strategically on an enterprise scale, or by leveraging individual components to solve project-level challenges, our customers can use MKS’s technology to better enable higher levels of process maturity, better manage global development activity and safeguard their most critical business applications and software assets. Under its widely known MKS Toolkit brand, MKS also provides UNIX-Windows co-existence and system administration that significantly cut development and administrative costs and reduce time to market, while enabling enhanced performance. More information about MKS can be found at http://www.mks.com, or by calling 1-800-265-2797 (US & Canada), +49-711-351775-0 (Germany), +44-1483-733900 (United Kingdom) and 1-519-884-2251 (Rest of World).

Copyright © 2005 MKS Inc. MKS and design, and MKS Toolkit are trademarks or registered trademarks of MKS Inc. All other trademarks mentioned in this release are the property of their respective owners.

This news release contains forward-looking statements that involve risks and uncertainties, which may cause actual results to differ materially from the statements made. When used in this document, the words "may", "would", "could", "will", "intend", "plan", "anticipate", "believe", "estimate", "expect" and similar expressions are intended to identify forward-looking statements. Such statements reflect the Company’s current views with respect to future events and are subject to such risks and uncertainties. Many factors could cause our actual results to differ materially from the statements made including those factors detailed from time to time in filings made by the Company with Canadian securities regulatory authorities. Should one or more of these risks or uncertainties materialize, or should assumptions underlying the forward looking statements prove incorrect, actual results may vary materially from those described herein as intended, planned, anticipated or expected. The Company does not intend and does not assume any obligation to update these forward-looking statements.

Investor Contact:
Douglas Sawatzky, CFO
519-883-3252
Email dsawatzky@mks.com