PROBLEM TO BE SOLVED: To provide a treatment instrument which shows high incision performance and enables a smooth incision operation for performing an operation from an incision to a collection.SOLUTION: A treatment instrument (1) in the invention includes: a treatment member (20) having a snare wire (2) with a first loop shape and an operation wire (3) whose distal end is connected to the snare wire； and a collection member (30) having a collection distal end part (5) which has a second loop shape and has elastic restoration force that is greater than that of the snare wire and a collection operation part (6) that can retract relative to the operation wire. The treatment member is configured to change from a first state in which the snare wire makes contact with and engages the collection distal end part, following the second loop shape to a second state in which the snare wire forms a loop smaller than the second loop shape by cancelling the engagement with the collection distal end part. The collection member is configured to change into a collection state to reduce a diameter of the second loop shape of the collection distal end part after the second state.SELECTED DRAWING: Figure 2COPYRIGHT: (C)2020,JPO&INPIT【課題】切開性能が高く、切開操作が円滑に行え、切開から回収までの操作を行える処置具を提供する。【解決手段】本処置具（１）は、第一ループ形状を有するスネアワイヤ（２）、及び先端が前記スネアワイヤに連結された操作ワイヤ（３）を有する処置部材（２０）と、第二ループ形状を有し前記スネアワイヤよりも弾性復元力が大きい回収先端部（５）及び前記操作ワイヤに対して後退可能な回収操作部（６）を有する回収部材（３０）と、を備え、前記処置部材は、前記スネアワイヤが前記第二ループ形状に沿って前記回収先端部に接触して係止された第一状態から、前記スネアワイヤが前記回収先端部との係止が解除されて前記第二ループ形状よりも小さいループを形成する第二状態に変更可能に構成され、前記回収部材は、前記第二状態後、前記回収先端部の前記第二ループ形状を縮径する回収状態に変更可能に構成されている。【選択図】図２
