To provide a reflective projection optical system of a compact five- mirror system which is applicable to an EUV (extreme ultraviolet) lithography system and balanced between resolving power and a throughput, and to provide an exposure device and a method for manufacturing a device.

The five mirrors which reflect light in order of a first mirror (M1), a second mirror (M2), a third mirror (M3), a fourth mirror (M4) and a fifth mirror (M5) are arranged in order from an object side to an image side so as to fundamentally form a coaxial system. Light flux advancing from the first mirror (M1) to the second mirror (M2) crosses light flux advancing from the third mirror (M3) to the fourth mirror (M4).