A color separation prism includes a filter, a first prism, a second prism, and a third prism. The first prism allows incidence of light transmitted through the filter, and the first reflective film reflects a first color component of the visible light and a part of the invisible light, among the light beams incident on the first prism. The second prism emits the light reflected by a second reflective film, and the second reflective film reflects the second color component of the visible light and a part of the invisible light, among the light beams incident on the second prism. The third prism emits the light transmitted through the second reflective film. The first reflective film and the second reflective film allocate the invisible light and the visible light emitted from each prism so as to obtain approximately uniform amount of the light.