Projection optical system and projection exposure apparatus using the same

A projection exposure apparatus for transferring a pattern formed on a mask onto a photosensitive substrate, comprising:

• an illumination optical system for emitting an illumination light beam;
• a mask stage for supporting the mask illuminated with the illumination light beam from said illumination optical system;
• a substrate state for supporting the photosensitive substrate,;
• and
• a projection optical system for making a position on the mask placed on said mask stage conjugate to a position on the photosensitive substrate placed on said substrate stage, said substrate stage positioning the substrate in a direction perpendicular to an optical axis of said projection optical system,
• wherein said projection optical system comprises a correction target optical system having a lease one of an optical member for refracting a light beam, and a correction optical member having a diffraction optical element, said correction optical member being arranged such that a direction of focal position movement caused by an environmental change during an operation along an optical axis direction of said correction target optical system is opposite to that of focal position movement of said correction target optical system, which is caused along the optical axis direction by the same environmental change.