EXHIBIT 21

ESI Subsidiaries

As of April 2, 2011



|                                                   |  |                               |  |                                    |     |  
|-------------------------------------------------- |  | ----------------------------- |  | ---------------------------------- | --- | -
|Name                                               |  | State/Country ofIncorporation |  | Percentageof VotingSecuritiesOwned |    
|                                                   |  |                              
|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 | %
|                                                   |  |                              
|New Wave Research, Inc.                            |  | California                    |  |                                    | 100 | %
|                                                   |  |                              
|New Wave Research, Ltd. (FSC)                      |  | Virgin Islands                |  |                                    | 100 | %
|                                                   |  |                              
|New Wave Research, Ltd.                            |  | Hong Kong                     |  |                                    | 100 | %
|                                                   |  |                              
|ESI-Pyrophotonics Lasers, Inc.                     |  | Canada                        |  |                                    | 100 | %