Projection exposure apparatus

摘要

A is a projection exposure apparatus has a light sending optical system exhibiting a high degree of freedom of light sending. The light sending optical system comprises a light introducing system for introducing light beams from a predetermined light source into a substrate stage, and a light irradiating system for irradiating a predetermined area with the light beams introduced into the substrate stage by the light introducing system. The light introducing system and the light irradiating system are mechanically separated but optically connectable only when the substrate stage is in a specified positional relationship with respect to the projection optical system.