This endoscope treatment tool (1) comprises: a tubular sheath part (61)； an operation wire (62) that is arranged inside the sheath part (61) and that can project from and retract into a distal end of the sheath part (61)； an arm member (11) that is connected to a distal end of the operation wire (62), has a pair of distal end parts, and can open and close； a holding tube (31) that is arranged at the distal end of the sheath part (61), a portion of the arm member (11) being inserted in the holding tube； and a biasing member (39) that is arranged between the arm member (11) and the holding tube (31), the biasing member having a biasing force for moving the arm member (11) toward the distal end side of the holding tube (31). The arm member (11) and the holding tube (31) respectively have projections (12b, 13b) and engagement parts (33) serving as a rotation restricting structure that prevents the arm member (11) from rotating about the axis of the holding tube (31) in a state where the arm member (11) is in contact with the holding tube (31) against the biasing force of the biasing member (39).Cet outil de traitement endoscopique (1) comprend : une gaine tubulaire (61), un câble de fonctionnement (62) à l'intérieur de la gaine (61) qui sort de l'extrémité distale et se rétracte (61), un bras (11) qui est relié à l'extrémité distale du câble d'actionnement (62) qui peut s'ouvrir et se fermer, un tube de maintien (31) à l'extrémité distale de la gaine (61), une partie du bras (11) insérée dans le tube de maintien, et un élément de sollicitation (39) entre le bras (11) et le tube de maintien (31). L'élément de sollicitation déplace le bras (11) vers l'extrémité distale du tube de maintien (31). Le bras (11) et le tube de maintien (31) ont des parties saillantes (12b, 13b) et des parties d'engagement (33) servant de structure de limitation de la rotation, qui empêche le bras (11) de tourner autour de l'axe du tube de maintien (31) lorsqu'il est en contact avec celui-ci.内視鏡
