A liquid crystal rear projector device of the present invention includes a lamp unit providing a light source, a cooling fan for cooling the lamp unit, and an optical system for generating color image light with the lamp unit providing a light source, the lamp unit including a light emitting tube providing a light source, and a reflector for reflecting light emitted from the light emitting tube toward the optical system. The reflector has an air introduction hole for introducing air discharged from the cooling fan into the reflector, which is provided near the spherical portion of the light emitting tube, and faces to a vertical top of the spherical portion to blow the air to the top.