A medical treatment instrument is provided with a sheath, an operating member which is inserted into the sheath, a treatment section which is provided at the distal end of the operating member, and an operating section which is provided at the proximal end of the sheath, moves the operating member in the axial direction, and rotates the operating member about the axis. The operating section has: a body section which is provided at the proximal end of the sheath and which has a body-side finger-hold section a slide section which is adapted to be movable in the axial direction relative to the body section, the slide section having the proximal end of the operating member affixed thereto, the slide section having a slide-side finger-hold section provided further toward the distal end side than the body-side finger-hold section in the axial direction and a restriction section which can be switched between a movable state in which the slide section can move in the axial direction relative to the body section and a restricted state in which the movement of the slide section relative to the body section toward the proximal end side is restricted. The restriction section can be switched between the restricted state and the movable state by moving a part of the restriction section in the axial direction.La présente invention concerne un instrument de traitement médical équipé dune gaine, dun élément dactionnement qui est inséré dans la gaine, dune section de traitement qui est prévue au niveau de lextrémité distale de lélément dactionnement, et dune section dactionnement qui est prévue au niveau de lextrémité proximale de la gaine, qui déplace lélément dactionnement dans la direction axiale et entraîne en rotation lélément dactionnement autour de laxe. La section dactionnement comporte : une section corps qui est prévue au niveau de lextrémité proximale de la gaine et qui présente une section de préhension de doigt côté corps une section coulissante qui est adaptée à être m
