EXHIBIT 21

ESI Subsidiaries

As of June 2, 2007



|                                                   |  |                                |  |                                       |  
|-------------------------------------------------- |  | ------------------------------ |  | ------------------------------------- | -
|Name                                               |  | State/Country of Incorporation |  | Percentage of Voting Securities Owned |  
|ESI F.S.C. (dormant)                               |  | Guam                           |  | 100                                   | %
|                                                   |  |                               
|Electro Scientific Industries GmbH                 |  | Germany                        |  | 100                                   | %
|                                                   |  |                               
|ESI International Corp.                            |  | Oregon                         |  | 100                                   | %
|                                                   |  |                               
|Electro Scientific Industries Japan Co., Ltd.      |  | Japan                          |  | 100                                   | %
|                                                   |  |                               
|ESI Korea Co. Ltd.                                 |  | Korea                          |  | 100                                   | %
|                                                   |  |                               
|Electro Scientific Industries Europe Ltd.          |  | United Kingdom                 |  | 100                                   | %
|                                                   |  |                               
|Electro Scientific Industries, SARL                |  | France                         |  | 100                                   | %
|                                                   |  |                               
|Electro Scientific Industries Singapore PTE Ltd.   |  | Singapore                      |  | 100                                   | %
|                                                   |  |                               
|ESI China, Inc.                                    |  | Oregon                         |  | 100                                   | %
|                                                   |  |                               
|ESI Electronic Equipment (Shanghai) Co., Ltd.      |  | China                          |  | 100                                   | %
|                                                   |  |                               
|ESI (Beijing) R&D Center Co., Ltd.                 |  | China                          |  | 100                                   | %
|                                                   |  |                               
|ESI Technology Development, Pte. Ltd.              |  | Singapore                      |  | 100                                   | %
|                                                   |  |                               
|ESI China R&D Investment, Pte. Ltd.                |  | Singapore                      |  | 100                                   | %
|                                                   |  |                               
|ESI Taiwan (Branch Office)                         |  | Taiwan                         |  | 100                                   | %
|                                                   |  |                               
|ESI (Beijing) Electro Optic Manufacturing Co. Ltd. |  | China                          |  | 100                                   | %