Abstract: The directions of amplitude of polarized light passing through a polarizer are concentric around a position. The polarizer is disposed on the surface of a pupil such that the position lies exactly on the center of the surface of the pupil. Rays of luminous flux of illumination light converted into polarized light by the polarizer are converged onto a wafer with concentric planes of polarization with respect to an optical axis. The illumination light is therefore incident on a photoresist as s-polarized light. Thus, the amount of light entering the photoresist is less likely to depend upon the angle of incidence. Consequently, the contrast of an optical image formed in the photoresist is improved, and hence, resolution characteristics are improved.