An extreme ultra violet light source device of a laser produced plasma type, in which charged particles such as ions emitted from plasma can be efficiently ejected. The extreme ultra violet light source device includes: a target nozzle that supplies a target material; a laser oscillator that applies a laser beam to the target material supplied from the target nozzle to generate plasma; collector optics that collects extreme ultra violet light radiated from the plasma; and a magnetic field forming unit that forms an asymmetric magnetic field in a position where the laser beam is applied to the target material.