Patent ID: 7130018

Claim:
A catoptric projection optical system for projecting a reduced image of a pattern on an object surface onto an image surface, said catoptric projection optical system comprising eight mirrors that includes, in order from the object surface side to the image surface side, a first mirror, a second mirror, a third mirror, a fourth mirror, a fifth mirror, a sixth mirror, a seventh mirror, and an eighth mirror, and forming an intermediate image between said sixth mirror and said seventh mirror on an optical path, wherein a position in a height direction of a principal ray from an optical axis at each mirror displaces, and a displacement direction from the first mirror to said fourth mirror is reverse to that from said fifth mirror to said eight mirror, wherein said second to fifth mirrors are concave, convex, concave and concave mirrors, respectively, and said seventh and eighth mirrors are convex and concave mirrors, respectively, and wherein said second mirror among these eight mirrors is located closest to the object surface side.