PROBLEM TO BE SOLVED: To provide an endoscopic surgical instrument in which the gripping and fixing of tissue can be made by a simple structure, and electrocautery, electrocoagulation, resection, mobilization, separation, and traction of the tissue are performed, and further, the removal of blood clotting stuck to a hook during surgery and the take-out of a sample for the living body pathological examination can be made.SOLUTION: A small diameter endoscope surgical instrument comprises: an inner tube 20 having the same outer diameter as a small diameter endoscope 10 to be used, being used when the small diameter endoscope surgical instrument is inserted into a body, and capable of being replaced with the small diameter endoscope 10 after the insertion； a guide pipe 30 with the small diameter endoscope or the inner tube inserted therein, and supporting them in the state capable of being axially moved； and a processing pipe 40 with processing means such as an electrode, a blade, and a hook in the distal end, the processing pipe that has the guide pipe inserted therein and supports it in the state capable of being axially moved. The small diameter endoscope, the inner tube, the guide pipe, and the processing pipe have independent operation units in the proximal end, respectively, and thereby respective axial positions and the rotation angles can be changed.SELECTED DRAWING: Figure 1【課題】簡単な構成で、組織の把持や固定ができ、組織の電気焼灼、電気凝固、切除、授動、分離、牽引を行い、さらに、手術中にフックにこびりついた凝血塊等の除去や、生体病理検査用の試料の取り出しができる内視鏡手術器具を提供する。【解決手段】使用する細径内視鏡１０と同じ外径を有し、細径内視鏡手術器具を体内に挿入する際に使用し、挿入後には細径内視鏡１０と置き換えられる内管２０と、細径内視鏡または内管が挿入され、それらを軸方向に移動可能な状態で支持するガイドパイプ３０と、ガイドパイプが挿入され、それを軸方向に移動可能な状態で支持する処理パイプで、その先端部に電極、刃、フック等の処理手段を有する処理パイプ４０とから成り、細径内視鏡、内管、ガイドパイプ、及び、処理パイプが、各々その近端部に独立した操作部を有し、これらにより、各々の軸方向の位置と回転角度を変えうる細径内視鏡手術器具。【選択図】図１
