An actuator for a treatment tool including: a tube having a distal end configured to rotatably support the treatment tool； a twisting wire disposed along a longitudinal axis of the tube, the twisting wire having a distal end and a proximal end, the treatment tool being connected to the distal end of the twisting wire, the twisting wire being actuated by applying a tensile force at the proximal end, the twisting wire converting the tensile force into rotation of the treatment tool around the longitudinal axis of the tube； and at least one wire movable in a longitudinal direction to actuate the treatment tool, the at least one wire actuating the treatment tool separately from actuation of the twisting wire to rotate the treatment tool.
