A light source apparatus for irradiating a laser light onto a target, for generating plasma, and for producing light from the plasma, said light source apparatus includes a first detection part for detecting a position of the target, an adjusting part for adjusting a position of a condenser point of the laser light, and a first controller for controlling the adjusting part so that the position of the target detected by the first detection part is corresponding to the condenser point of the laser light.