Abstract: An illumination optical apparatus that illuminates an object with illumination light includes a first spatial light modulator in an optical path of the illumination light, and having a plurality of first mirror elements; a second spatial light modulator in the optical path of the illumination light from the first spatial light modulator, and having a plurality of second mirror elements; a control unit which controls the first and second spatial light modulators to control postures of the first and second mirror elements; and an optical integrator in the optical path of the illumination light from the second spatial light modulator on an incidence side of an illumination pupil plane of the illumination optical apparatus. The control unit controls the postures of the first and second mirror elements to set a light intensity distribution of the illumination light on the illumination pupil plane.