An object of the present invention is to widen a range in which line of sight change is possible, particularly in a pan direction. According to the present invention it is possible to acquire high line of sight changing speed. A pan mirror is capable of rotation in forward and reverse directions about a third rotational axis. Also, the third rotational axis extends in a direction that is substantially parallel to a line of sight direction directed from a tilt direction control section to the pan mirror. An angle α formed by the pan mirror and the third rotational axis is set in a range 0°