An exposure apparatus includes a projection optical system for projecting a pattern on a reticle onto an object to be exposed, a reference mark that serves as a reference for an alignment between the reticle and the object, a first fluid that has a refractive index of 1 or greater, and fills a space between at least part of the projection optical system and the object and a space between at least part of the projection optical system and the reference mark, and an alignment mechanism for aligning the object by using the projection optical system and the first fluid.