Mounting The endoscope treatment instrument, and the sheath, the distal end of the sheath a support portion that is, the pair of forceps members are rotatably supported around a pivot shaft provided on the supporting part, movably inserted in the sheath, the above and as the distance from the pivot axis The opposing faces respectively provided on the forceps members to close together, and the line portion for separating the pair of opposing surfaces to each other in accordance with approaching to the rotating shaft, and a locking portion provided on the supporting part, the The movement and the locking portion provided in the linear portion, in the longitudinal direction of the sheath, the distal end side of the distal end position from the reference position from the reference position the position of the distal end portion of the linear portion to the engaged portion and a moving mechanism for causing.この内視鏡処置具は、シースと、前記シースの先端側に取り付けられた支持部と、前記支持部に設けられた回動軸周りに回動可能に支持された一対の鉗子部材と、前記シースに進退可能に挿通され、前記回動軸から離間するにしたがって前記鉗子部材にそれぞれ設けられた対向面を互いに接近させ、前記回動軸に接近するにしたがって一対の前記対向面を互いに離間させる線状部と、前記支持部に設けられた係止部と、前記線状部に設けられた被係止部と、前記シースの長手方向において、前記被係止部に対する前記線状部の先端部の位置を基準位置から前記基準位置より先端側の先端位置に移動させるための移動機構とを備える。
