In lamp unit 10 having
light source lamp 1, reflector 2 for reflecting light from
light source lamp 1, reflector holding member 11, and reflector cover 15, a plurality of cooling holes 18a are formed in a region of reflector holding member 11 provided with lamp unit positioner 16a. Cooling holes 18a are open toward an upper
bulb area, a lower
bulb area, and a
cathode of the
light source lamp, respectively. Stud 22a for fixing reflector holding member 11 has a throughhole extending at the center thereof, so that cooling air fed from high static pressure blower 27 can be sent to cooling holes 18 through tube 28 and the throughhole of stud 22a, thus efficiently cooling the upper
bulb area, lower bulb area, and
cathode of light source lamp 1 in a concentrative manner with a small amount of air. Thus, the resulting lamp unit, provided by the present invention, can reduce the amount of air required for cooling the lamp, and can use a high static pressure and small fan.