Abstract: In an extreme ultra violet light source apparatus of a laser produced plasma type, charged particles such as ions emitted from plasma are promptly ejected to the outside of a chamber. The extreme ultra violet light source apparatus includes a chamber in which extreme ultra violet light is generated, a target supply unit for supplying a target material to a predetermined position within the chamber, a driver laser for applying a laser beam to the target material supplied by the target supply unit to generate plasma, a collector mirror for collecting the extreme ultra violet light radiated from the plasma to output the extreme ultra violet light, a magnetic field forming unit for forming an asymmetric magnetic field in a generation position of the plasma by using a coil, and a charged particle collection mechanism provided on at least one of two surfaces of the chamber to which lines of magnetic force generated by the coil extend.