A light controller includes a substrate having an optical path opening, a blade unit with a blade mounted on the substrate for opening and closing the optical path opening, a driver unit for driving the blade, and a stopper unit for restricting a movement of the blade between an open position and a closed position. The stopper unit includes a long hole formed in the blade and extending in a direction that the blade moves, and a stopper pin fitted into the long hole. The long hole is disposed at a position away from the optical path opening in an entire range that the blade moves. Accordingly, when the blade unit has a plurality of blades, it is necessary to arrange only the stopper pins having a number equal to the number of the blades on the substrate, thereby reducing a size of an apparatus.