The endoscope treatment tool (1) has a distal end and a proximal end, a shaft (2) having a lumen along the longitudinal axis, and a blade provided between the distal end and the proximal end of the shaft (2). (8), a distal-side index (11) disposed on the blade (8), and a proximal-side index disposed on the proximal side of the shaft (2) on the blade (8) with respect to the distal-side index (12), and when the tip of the shaft (2) is located at a branch portion between the common bile duct and the gallbladder duct in a state where the shaft (2) is raised by the raising base of the endoscope, The distal-side index (11) is located in the observation field of view by the observation optical system of the endoscope, and the proximal side is located when the distal end of the shaft (2) is located at a branch portion between the right liver tube and the left liver tube. The index (12) is located within the observation field of view by the observation optical system of the endoscope. 内視鏡用処置具（１）は、先端と基端を有し、長手軸に沿ってルーメンを有するシャフト（２）と、シャフト（２）の先端と基端との間に設けられたブレード（８）と、ブレード（８）上に配置された先端側指標（１１）と、ブレード（８）上に前記先端側指標よりもシャフト（２）の基端側に配置された基端側指標（１２）と、を有し、シャフト（２）を内視鏡の起上台により起上させた状態において、シャフト（２）の先端が総胆管と胆嚢管との分岐部分に位置するときに、先端側指標（１１）は、内視鏡の観察光学系による観察視野内に位置し、シャフト（２）の先端が右肝管と左肝管との分岐部分に位置するときに、基端側指標（１２）は、内視鏡の観察光学系による観察視野内に位置する。
