An ion wind generator (20) is arranged in the vicinity of a light source (1). The ion wind generator (20) allows an air flow by negatively ionizing air by corona discharges using negative side needle electrodes (21), and drawing the negatively-ionized air using a ground side mesh electrode (22). High-temperature air surrounding the light source (1) is drawn by the air flow and exhausted from a exhaust port at a rear side of a casing. An ozone decomposition catalyst filter 23 is provided in the exhaust port. Ozone (O3) is generated by the corona discharges in the ion wind generator (20). However, the ozone is decomposed by passing through the ozone decomposition catalyst filter 23 provided at the exhaust port.