An endoscope system includes an insertion section inserted along a longitudinal axis of a lumen, a distal end configuration section provided at a distal end of the insertion section, a swinging motion of the treatment instrument at the distal end of the insertion section A long pulling member connected to the oscillating table in the distal end constituting portion and allowing the oscillating table to be remotely operated, a distal end thereof being watertightly connected to a distal end side of the pulling member or the oscillating table , A tubular elastic member whose rear end is water-tightly connected to the distal end constituent part and covers the pulling member, a tubular cover attached to the distal end constituent part and having an opening on the circumferential surface, and a cover A cover detaching tool capable of pressing an edge of the opening portion in a state of being engaged with the cover removing tool in a state where the cover detaching tool is engaged with the cover, At a position spaced apart from the position in the longitudinal direction A projection and in contact with the edge of the opening, the.内視鏡システムは、管腔に対し長手軸に沿って挿入される挿入部と、前記挿入部の先端に設けられる先端構成部と、前記挿入部の先端において、処置具を揺動させる揺動台と、前記先端構成部内において前記揺動台と接続し、該揺動台を遠隔操作させる長尺な牽引部材と、先端が前記牽引部材の先端側又は前記揺動台と水密的に接続し、後端が前記先端構成部と水密的に接続し、前記牽引部材を覆う管状の弾性部材と、前記先端構成部に装着されるとともに周面に開口部を有する筒形状のカバーと、前記カバーに係合した状態で、前記開口部の縁を押圧可能なカバー取り外し具と、前記カバー取り外し具に設けられ、前記カバー取り外し具を前記カバーに係合させた状態で、前記弾性部材の一端の位置から前記長手軸方向に離間した位置で前記開口部の縁に接触する突起と、を有する。
