The operation unit 30, wires 21u to 21l whose one end is connected to the bending portion and the other end is connected to the rotating body 31, and wire fixing portions 25u to 25l to which the other ends of the wires 21u to 21l are separately fixed, respectively. , And grooves 32u to 32l that restrict the intermediate portions of the wires 21u to 21l corresponding to the rotating direction of the rotating body 31 so as to be wound around the rotating body 31 in accordance with the rotation.操作ユニット３０と、一端に湾曲部が接続され、他端が回動体３１に接続されるワイヤ２１ｕ～２１ｌと、ワイヤ２１ｕ～２１ｌの他端がそれぞれ別個に固定されるワイヤ固定部２５ｕ～２５ｌと、ワイヤ２１ｕ～２１ｌにおける回動体３１が回転する方向に対応するワイヤの中間部を、回転に伴って回動体３１に巻き取るよう規制する溝３２ｕ～３２ｌと、を具備する。
