An exposure apparatus includes a projection optical system for projecting a pattern on a reticle mounted on a first stage onto an object mounted on a second stage, a first reference plate provided on the reticle or a surface equivalent to the reticle, the first reference plate having three or more first reference marks each of which serves as a reference for an alignment between the reticle and the object, a measuring unit for measuring focus position at imaging positions of the first reference marks and for measuring an image surface of the projection optical system, and a correcting unit for correcting a relationship between the image surface and a reference surface as a reference of a measurement by the measuring unit.