The present invention accomplishes an evaluation of image formation performance in which the influence of a coat is accurately reflected. According to the present invention, for the evaluation of image formation performance of an optical system obtained is a pupil transmittance distribution (a distribution of light transmittance on an exit pupil surface) of a light beam that enters an image point to be evaluated of the optical system. At least one of a rotational symmetrical component, an odd symmetrical component, and an even symmetrical component is extracted from the obtained pupil transmittance distribution as an evaluation index.