Exposure apparatus and device manufacturing method

摘要

This invention provides an exposure apparatus which exposes a substrate (51) with a pattern formed on a reticle (3), and includes a projection optical system (1) including an optical element (11 - 14) and a reflecting surface (42) which reflects light toward the projection optical system (1). The exposure apparatus further includes a processor (P) which obtains information indicating a surface condition of the optical element (11 - 14) based on first light which is incident on the projection optical system (1) and reflected by the reflecting surface (42) and a surface of the optical element (11 - 14) and second light which is incident on the projection optical system (1) and not reflected by the reflecting surface (42) and the surface of the optical element (11 - 14).