The purpose of the present invention is to switch the state of liquid supply depending on the open/closed state of forceps. This endoscope treatment tool (1) is provided with: a sheath (2) which has a conduit (2a) through which a liquid can be delivered, and can be inserted into a channel of an endoscope； a forceps part (3) which is disposed protruding from a distal cover (30) provided at the distal end of the sheath (2), and provided with a pair of forceps pieces (3a) capable of opening/closing； an operation member (4d) which is connected to the proximal end of the forceps part (3), and is moved forward in the longitudinal direction to open the forceps pieces (3a) and moved backward to close the forceps pieces (3a)； and a flow path forming member (7) having a through hole (7a) which allows the operation member (4d) to pass therethrough. The flow path forming member (7) forms a first liquid supply hole (9) which is the space between the through hole (7a) and the operation member (4d), and forms a second liquid supply hole (8) which is the space between the inner circumferential surface of the distal cover (30) and the flow path forming member (7). The operation member (4d) is provided with a large-diameter part which, when the operation member (4d) is moved forward, presses against the flow path forming member (7) and blocks the first liquid supply hole (9).La présente invention vise à commuter l'état d'alimentation en liquide en fonction de l'état ouvert/fermé de pince. Cet outil de traitement endoscope (1) comporte : une gaine (2) dotée d'un conduit (2a) à travers lequel un liquide peut être administré, et qui peut être insérée dans un canal d'un endoscope； une partie pince (3) qui est disposée en saillie d'un couvercle distal (30) située à l'extrémité distale de la gaine (2) et, et pourvue d'une paire de pièces de pince (3a) capable de s'ouvrir/se fermer； un élément d'opération (4d) qui est relié à l'extrémité proximale de la partie pince (3), et est déplacé vers
