An exposure apparatus which exposes a substrate with exposure light, includes a projection optical system which projects a pattern image of an original onto the substrate; a first illumination unit which illuminates the original with the exposure light; and a second illumination unit which guides illumination light that is different from the exposure light for exposing the substrate to the projection optical system, the second illumination unit includes a modifier which modifies an illumination distribution of the illumination light entering an optical element near a pupil of the projection optical system and an optical element which is the closest to the original in the projection optical system.