An reflective imaging optical system of the far pupil type, which is applicable to an exposure apparatus using for example the EUV light, forms on a second plane an image of a predetermined area on a first plane and is provided with first to eighth reflecting mirrors arranged in an order of reflection from the first plane toward the second plane. An entrance pupil of reflective imaging optical system is positioned on a side opposite to the reflective imaging optical system with the first plane intervening therebetween; and the following condition is fulfilled provided that PD represents a distance along an optical axis between the entrance pupil and the first plane, TT represents a distance along the optical axis between the first plane and the second plane, and R represents an angle of incidence of a main light beam coming into the first plane: −14.3