Abstract: A light source apparatus equipped with a GaN type semiconductor laser, wherein deformation of the shape of the light spot due to fluctuations in the drive current of the light emitting element is prevented, is provided. A light source apparatus equipped with a GaN type semiconductor laser is provided with a slit panel or other spatial filter for eliminating stray light, which amounts to 20% or less of the total output occurring when the GaN type semiconductor laser is driven at maximum output, from the light emitted from the GaN type semiconductor laser.