The child endoscope (1) as a medical device holds the pivoting members (22a, 22b) and the pivoting members (22a, 22b) rotatably around a predetermined pivoting axis (CX1), and An exterior member (11a) having a surface (11C) in the outer peripheral portion that accommodates the rotating members (22a, 22b) inside and that contacts a part of the outer peripheral surface of the operation portion (101) of the parent endoscope (2) And the rotation member (22a, 22b), when the exterior member (11a) is viewed from the direction orthogonal to the rotation axis (CX1), the inside of the width of the exterior member (11a) in the rotation axis direction And a bending operation lever (14a, 14b) disposed on the医療デバイスとしての子内視鏡（１）は、回動部材（２２ａ、２２ｂ）と、回動部材（２２ａ、２２ｂ）を所定の回動軸（ＣＸ１）周りに回動可能に保持し、かつ回動部材（２２ａ、２２ｂ）を内部に収容すると共に、親内視鏡（２）の操作部（１０１）の外周面の一部に接触する面（１１Ｃ）を外周部に有する外装部材（１１ａ）と、回動部材（２２ａ、２２ｂ）に設けられ、外装部材（１１ａ）を回動軸（ＣＸ１）に直交する方向から見たときに回動軸方向における外装部材（１１ａ）の幅の内側に配置された湾曲操作レバー（１４ａ、１４ｂ）とを有する。
