An image display apparatus has a reflective display device, an illumination optical system with a reflective surface A for guiding light from a light source to the display device, and a display optical system for guiding light from the display device to an observer's observation position and is constructed to permit an observer to observe image information displayed on the display device. The image display apparatus is constructed in appropriate setting of principal rays emerging from a display surface of the display device and impinging upon the center of the exit pupil, illumination principal rays emerging from the light source and guided to the display surface by the illumination optical system to become principal rays, angles of incidence and emergence of the illumination principal rays and the principal rays to and from the display surface, an angle between the reflective surface A and the display surface, angles of incidence of the illumination principal rays to the reflective surface A, and so on.