The endoscopic treatment tool , a sheath , and a support portion attached to the distal end of the sheath is disposed in front of the sheath is relatively rotatably supported on the pivot axis provided in the supporting part pair and the forceps members , retractably and is inserted into the sheath together is allowed to close the opposed faces respectively provided on the front end side of the rotation shaft in the pair of forceps members and as the distance from the pivot axis , approaching the pivot axis It includes a linear member for separating a pair of opposed surfaces to each other , and an elastic member supported on the linear member or support portion and a locking portion provided in the linear member or forceps members accordingly.内視鏡処置具は、シースと、シースの先端部に取り付けられた支持部と、シースより前方に配置され支持部に設けられた回動軸回りに相対的に回動可能に支持された一対の鉗子部材と、シースに進退可能に挿通され、回動軸から離間するにしたがって一対の鉗子部材における回動軸より先端側にそれぞれ設けられた対向面を互いに接近させ、回動軸に接近するにしたがって一対の対向面を互いに離間させる線状部材と、線状部材または支持部に支持された弾性部材と、線状部材または鉗子部材に設けられた係止部とを備える。
