To lower a noise value during drive.

The projection display device 1 is provided with a lamp unit 21 having has a power bulb 24 as a light source in a casing 2, and a prism block part 20 having has a cross prism 19 which composites colors of light of a prescribed wavelength band of light valves 17R, 17G and 17B to perform the modulation or the like of the light, and projects the light emitted from the power bulb and made incident on the prism block part through a projection lens 26. The projection display device 1 is further provided with a suction fan 25 to capture a cooling wind in a casing through an inlet 28, and an exhaust fan 27 to exhaust the captured cooling wind out of the casing through an outlet 29. The suction fan is arranged under the prism block part, the exhaust fan is arranged under the lamp unit, and the inlet and the outlet are formed in the bottom surface part 2a of the casing.