An optical switch of the present invention includes at least one input optical fiber, output optical fibers, at least one movable mirror for directing a light beam from the input optical fiber selectively to one of the output optical fibers, and at least one shutter for appropriately intercepting the light beam traveling toward the movable mirror from the input optical fiber. A direction of the movable mirror is changeable, and the direction of the movable mirror is changed to switch the output optical fiber that combines with the light beam reflected by the movable mirror. The shutter intercepts the light beam traveling toward the movable mirror while the direction of the movable mirror is changed.