A deflecting device and surveying instrument comprising a holding member having a ring shape; ring gears disposed on both sides of the holding member with the holding member interposed the ring gears, the ring gears being concentric with the holding member; bearings disposed between the holding member and the ring gears on both sides of the holding member, the bearings being concentric with the holding member; optical deflecting members disposed at central portions of the ring gears and integrated with the ring gears; deflection motors corresponding to the respective ring gears; and a drive transmitting member configured to transmit rotary force of the deflection motors to the ring gears.