An exposure apparatus comprising an illumination optical system configured to illuminate a reticle with a light beam from a light source, and a projection optical system configured to project a pattern image of the reticle onto a substrate, the illumination optical system including a light-shielding member which is arranged near a plane conjugate to a pupil plane of the projection optical system and which can move along an optical axis of the illumination optical system, wherein the light-shielding member is moved such that a light intensity distribution on the pupil plane of the projection optical system becomes nonuniform.