A deflector comprising: a first deflection mechanism including a movable unit swingable about a first axis and a drive unit for driving to swing the movable unit; a second deflection mechanism for driving to rotate the first deflection mechanism about a second axis different from the first axis; a contactless power supply unit including a second coil that is electrically connected to the drive unit and is located to rotate about the second axis along with the rotating second deflection mechanism, and a first coil that is located to face the second coil on a common axis, the contactless power supply unit for supplying power from the first coil to the second coil in accordance with an electromagnetic induction system; a light emitter and a light receiver located on the second axis; a light deflecting unit provided at the movable unit, for deflecting and reflecting measurement light emitted from the light emitter along the second axis and guiding, to the light receiver, light reflected by an object out of the measurement light thus deflected and reflected; a reference reflection member irradiated with the measurement light emitted from the light emitter and deflected and reflected by the light deflecting unit; and a swing controller for controlling the drive unit in accordance with reflected light from the reference reflection member and received by the light receiver, and characterized in that the reference reflection member includes regions (60A, 60B) of different reflectance along the second axis, and the swing controller includes an amplitude detector for detecting swing amplitude by the first deflection mechanism in accordance with the reflected light from the reference reflection member and received by the light receiver, and an amplitude controller for controlling the drive unit such that the swing amplitude detected by the amplitude detector has a predetermined value, and wherein a control signals is transmitted from the amplitude controller to the drive unit by way of a contactless signal transmission unit. a first deflection mechanism including a movable unit swingable about a first axis and a drive unit for driving to swing the movable unit; a second deflection mechanism for driving to rotate the first deflection mechanism about a second axis different from the first axis; a contactless power supply unit including a second coil that is electrically connected to the drive unit and is located to rotate about the second axis along with the rotating second deflection mechanism, and a first coil that is located to face the second coil on a common axis, the contactless power supply unit for supplying power from the first coil to the second coil in accordance with an electromagnetic induction system; a light emitter and a light receiver located on the second axis; a light deflecting unit provided at the movable unit, for deflecting and reflecting measurement light emitted from the light emitter along the second axis and guiding, to the light receiver, light reflected by an object out of the measurement light thus deflected and reflected; a reference reflection member irradiated with the measurement light emitted from the light emitter and deflected and reflected by the light deflecting unit; and a swing controller for controlling the drive unit in accordance with reflected light from the reference reflection member and received by the light receiver, and characterized in that the reference reflection member includes regions (60A, 60B) of different reflectance along the second axis, and the swing controller includes an amplitude detector for detecting swing amplitude by the first deflection mechanism in accordance with the reflected light from the reference reflection member and received by the light receiver, and an amplitude controller for controlling the drive unit such that the swing amplitude detected by the amplitude detector has a predetermined value, and wherein a control signals is transmitted from the amplitude controller to the drive unit by way of a contactless signal transmission unit.