Patent ID: 8395133

Claim:
An extreme ultraviolet light source device that generates extreme ultraviolet light by irradiating laser beam on a target material for turning the target material into plasma, comprising: a target material supply unit that supplies the target material into a chamber; a laser oscillator that outputs laser beam; an amplification system that amplifies the laser beam output from the laser oscillator by at least one amplifier; and a focusing system for irradiating the laser beam, amplified by the amplification system, on the target material in the chamber, at least the amplification system being provided with at least one first detection unit that detects a direction of laser beam and a shape of a wave front thereof in the amplification system, or detects beam parameters equivalent to the direction of the laser beam and the shape of the wave front thereof in the amplification system, at least one first compensation unit that compensates the direction of the laser beam and the shape of the wave front thereof which are detected by the first detection unit to a predetermined direction and a predetermined wave front shape, and at least one compensation control unit that controls a compensation operation by the first compensation unit according to a result of detection performed by the first detection unit.