Patent ID: 6885433

Claim:
An illumination apparatus provided in an exposure apparatus which exposes an object with an illumination beam via a mask to illuminate with the illumination beam an area on a predetermined plane on which a pattern surface of the mask is placed, comprising: an illumination optical system provided on an optical path through which the illumination beam passes, that includes a plurality of optical members arranged along an optical axis substantially perpendicular to the predetermined plane of which the area is illuminated via the plurality of optical members with the illumination beam having one of plural intensity distributions different from each other on a pupil plane of the illumination optical system; and a shaping optical system provided on the optical path in the illumination optical system to shape the plural intensity distributions of which a first one has an increased intensity portion apart from the optical axis relative to a portion of the first intensity distribution on the optical axis, that includes diffraction optical elements of which one is provided on the optical path to shape the first intensity distribution and is exchanged for another one of the diffraction optical elements to shape a second one of the plural intensity distributions different from the first intensity distribution.