GT Solar (SOLR) Receives $460.4 Million Order for Advanced Sapphire Crystallization Furnaces

Jun. 3, 2011 (Business Wire) — GT Solar International, Inc. (NASDAQ: SOLR), a global provider of polysilicon production technology, and sapphire and silicon crystalline growth systems and materials for the solar, LED and other specialty markets, today announced that it has received an order for its advanced sapphire crystallization furnaces totaling $460.4 million from a new market entrant. The order is GT’s largest single order to date, and represents a significant milestone for the company as a leader in the fast-growing LED industry. The order will be included in GT’s backlog for its current Q1 FY12, which ends on July 2, 2011.

“Our customer is a well established, diversified manufacturing company located in China who is new to the LED industry. We are pleased that they have selected our advanced sapphire growth technology for their new sapphire production facility,” said Tom Gutierrez, GT Solar’s president and CEO. “The market acceptance of our sapphire growth technology has been remarkable and it speaks to the confidence our customers have shown in our ability to help them build successful businesses that leverage our crystalline growth expertise and our global equipment installation and support resources.”

According to Strategies Unlimited, an industry analyst firm that tracks the LED industry, revenue for high brightness LED applications will be approximately $19 billion by 2015, with general lighting applications accounting for about 25 percent of this total. High brightness LEDs are primarily manufactured on sapphire wafers. This growth is driving the expansion of manufacturing capacity to meet the increased demand for high quality sapphire material.

About GT Solar International, Inc.

GT Solar International, Inc. is a global provider of polysilicon production technology, and sapphire and silicon crystalline growth systems and materials for the solar, LED and other specialty markets. The company’s products and services allow its customers to optimize their manufacturing environments and lower their cost of ownership. GT Solar will be changing its name to GT Advanced Technologies as it establishes a new global brand. The new name reflects the broader range of markets and technologies the company now addresses since its acquisition of Crystal Systems in July of 2010. The transition to GT Advanced Technologies is expected to be completed in August 2011. For additional information about GT Solar, please visit www.gtsolar.com.

Forward-Looking Statements

Some of the statements in this press release are forward-looking in nature, including statements regarding expected revenue from customer contracts and the expected performance of the sapphire furnaces. These statements are based on management’s current expectations or beliefs. These forward-looking statements are not a guarantee of performance and are subject to a number of uncertainties and other factors, many of which are outside the Company’s control, which could cause actual events to differ materially from those expressed or implied by the statements. Factors that may cause actual events to differ materially from those expressed or implied by our forward-looking statements include the possibility that the Company is unable to recognize revenue on customer contracts, that technological changes could render existing products or technologies obsolete, the Company may be unable to protect its intellectual property rights, competition from other manufacturers may increase, exchange rate fluctuations and conditions in the credit markets and economy may reduce demand for the Company’s products and various other risks as outlined in GT Solar International, Inc.’s filings with the Securities and Exchange Commission, including the statements under the heading “Risk Factors” in the Company’s annual report on Form 10-K for fiscal 2011 filed on May 26, 2011, and the quarterly report on Form 10-Q for the third quarter of fiscal 2011 filed on February 10, 2011. GT Solar International, Inc. is under no obligation to, and expressly disclaims any such obligation to, update or alter its forward-looking statements, whether as a result of new information, future events, or otherwise.

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GT Solar

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Jeff Nestel-Patt, 603-204-2883

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