An exposure apparatus includes an illumination optical system for illuminating a reflection mask that forms a pattern, by using light from a light source, wherein the illumination optical system includes a field stop that defines an illuminated area on the reflection mask, and has an opening, and an imaging system for introducing the light from the opening in the field stop into the reflection mask, the imaging system being a coaxial optical system, wherein a principal ray of the imaging system at a side of the reflection mask forming an inclination angle to a common axis of the coaxial optical system, the inclination angle being approximately equal to an angle between a principal ray of the projection optical system at the side of the reflection mask and a normal to a surface of the reflection mask.