To preferably shield high frequency noise generated at a lamp even if a lamp house has an opening for replacing a lamp.

A xenon lamp as the light source is housed in a lamp house 20 and an opening 23 to be a putting in/out port for lamp replacing is formed on the lamp house 20. A second lamp hatch 26 to shield noise generated at the xenon lamp is mounted on the opening 23. That is, protruding pieces 27 are inserted into holes on the lamp house 20 and fixed by a fixing screw 28, and an EMI spring 34 is placed between the lamp house 20 and the second lamp hatch 26 so as to give an electric contact. A plurality of ventilation holes 36 to keep noise shielding effect is formed on the second lamp hatch 26 to secure cooling action by a cooling fan 22.