To obtain a reflection refraction type projection optical system in which various aberrations such as color aberration are satisfactorily corrected to a light of ≤200nm wavelength, for example, and thereby, which has excellent imaging performance and can assure large image side numerical aperture required for high resolution.

The reflection refraction type projection optical system is provided with a reflection refraction type first imaging optical system (G1) which forms an intermediate image of a first face (R) and a refraction type second imaging optical system (G2) which forms a final image of the first face on a second face (W). The first imaging optical system has a first reflection surface (M1) formed on a lens surface for reflecting light transmitted through a first lens group (G11), a second reflection surface (M2) which guides light reflected by the first reflection surface to the second imaging optical system and a second lens group (G12) arranged in an optical path between the first reflection surface and the second reflection surface. An optical path between an optical surface at the most second face side and the second face in the second imaging optical system is filled with a medium having a refractive index substantially larger than 1.