Patent ID: 7615766

Claim:
A target supplier to be used in an extreme ultra violet light source device for generating extreme ultra violet light by irradiating a target material with a laser beam emitted from a laser light source to turn the target material into a plasma state, said target supplier comprising: a target nozzle that injects a target material in one of a liquid droplet state and a solid particle state; an electric charge supplying unit that supplies electric charge to the target material; a charge amount monitor including a first velocity monitor for observing a velocity of the target material supplied with the electric charge by said electric charge supplying unit, a measuring accelerator for forming an electrical field to accelerate the target material supplied with the electric charge by said electric charge supplying unit, and a second velocity monitor for observing a velocity of the target material accelerated by said measuring accelerator; a charge amount measuring unit that measures an amount of the electric charge supplied to the target material by said electric charge supplying unit based on output signals of said first velocity monitor and said second velocity monitor; control means that controls said electric charge supplying unit in a feedback manner based on a measurement result obtained by said charge amount measuring unit; and an accelerator that further accelerates the target material supplied with the electric charge by said electric charge supplying unit.