The inserting device includes a rotating member that is rotatable about a rotating shaft and an adjacent portion that is adjacent to both sides of the rotating member in a direction along the rotating shaft. The insertion device is provided in a state of forming an outer surface of the insertion portion and in an elastically deformed state in which an elastic force is applied toward the inner peripheral side of the insertion portion, And a film that maintains a state in which both ends of the rotating member are separated from the adjacent portion in the direction along the rotating shaft by adjusting the position in the direction along the rotating shaft.挿入機器は、回転軸を中心として回転可能な回転部材と、前記回転軸に沿う方向について前記回転部材の両側に隣設される隣設部と、を備える。前記挿入機器は、挿入部の外表面の一部を形成するとともに、前記挿入部の内周側に向かって弾性力を作用させる弾性変形した状態で設けられ、前記弾性力によって前記回転部材の前記回転軸に沿う前記方向についての位置を調整することにより、前記回転軸に沿う前記方向について前記回転部材の両端が前記隣設部から離間する状態を維持する皮膜とを備える。
