Disclosed herein a light source apparatus that is capable of suppressing a light transmission rate of a debris trap to be lowered and a reflection rate in a light condenser mirror to be lowered. In the light source apparatus, a shielding member is provided having an aperture is provided in front of a stationary type foil trap to limit a solid angle of light emitted from a high temperature plasma. Furthermore, the stationary type foil trap is provided with a driving mechanism to allow the foil trap to be revolved such that an adhesion part of the debris of the foil trap is deviated from a position of the foil trap facing the aperture.