A reflection-type variable optical attenuator comprises: a main attenuator unit including a first birefringent crystal plate, a Faraday rotational angle varying unit, and a second birefringent crystal plate arranged in this order; an input port and an output port that are arranged on a side of one end of the main attenuator unit; and a two-point reflection-type optical path varying reflector that is arranged on a side of the other end of the main attenuator unit. Light that comes in from the input port makes a round trip in the main attenuator unit and goes out through the output port.