A medical manipulator includes a wire movable in opposite directions, a driven wire having both ends thereof connected to the wire, an end effector of a distal-end working unit, a transmitting member, a crescent driven member integral with the transmitting member, and a return pulley. The transmitting member, the crescent driven member, and the return pulley are successively arranged in this order from the proximal end of the medical manipulator. When the driven wire is moved in opposite directions, the transmitting member also moves in opposite directions. At this time, the crescent driven member moves toward the return pulley, and the proximal-end portion of the return pulley enters a cavity of the crescent driven member.