An electronic device includes a first duct for guiding the air blown out from blowers for cooling a liquid crystal panel mounted on an illumination optical system to the liquid crystal panel, a second duct for guiding the air passing through the liquid crystal panel in the opposite direction of the air blown out from the blowers, a heat sink for removing heat from the air passing through the second duct and a blower holding unit for holding the blowers are provided in a dust-proof case, and the top surface of the blower holding unit, the blower holding unit forms a third duct for guiding the air from which heat has been removed by the heat sink to the air inlet of the blowers that is a space formed along the top surface of the dust-proof case.