Outer elongated insertion body rotating gears of detachably disposed insertion device substantially parallel to the central axis is defined in the longitudinal axis of the channel with an open end which opens to the outside by having external teeth of the rotational force transmitting unit a cylindrical rotating unit is disposed , in a state where the rotation gear is disposed in the open end of the channel , the central axis having internal teeth capable of meshing with the external teeth of the rotating gear has an inner gear to the axis rotatable and a tube for supporting the internal gear on the inner peripheral surface thereof .回転力伝達ユニットの外歯を有する回転ギアが着脱可能に配設される外側に開口した開口端部を有するチャンネルの長手軸に略平行な中心軸が規定された挿入装置の細長い挿入本体の外側に配設される筒状の回転ユニットは、前記チャンネルの開口端部に前記回転ギアが配設された状態で、前記回転ギアの外歯に噛み合わせ可能な内歯を有し前記中心軸の軸回りに回転可能な内歯車と、前記内歯車をその内周面に支持するチューブとを有する。
