A catadioptric optical system includes, in succession from the object side, a first partial optical system having positive refractive power and for forming the primary image of an object, and a second partial optical system having positive refractive power and for forming a secondary image by light from the primary image, and at least one aperture stop may be provided in the optical path of the first partial optical system and at least one aperture stop may be provided in the optical path of the second partial optical system.