An optical system (light guiding optical system) for guiding G-light and R-light to liquid crystal panels is protruded in an opposite direction from projection optical system with regard to an optical axis of a light source. A space is created between an optical engine and a wall surface, and air stream for suction fan is thus secured. A distance (H1) between the optical engine and the wall surface can be reduced to, for example, a thickness of an external housing of the projector. Since a unit comprising the light source and a suction fan is retracted in a direction of the projection optical system than a protruded portion of the light guiding optical system, a distance (H2) from an end edge of the optical engine to a projection light emitting position can be reduced.