An assisting tool for assisting the movement of the treatment tool having the insertion body inserted into the channel of the endoscope with respect to the channel includes a flexible portion forming an insertion path through which the treatment tool is inserted, A connecting portion which is provided on the endoscope and is connectable to the endoscope so as to make the channel and the insertion passage communicate with each other, a main body provided in the flexible portion and having a first joint, a main body having a first joint And a holding body having a second joint which is connected to the main body so as to be able to cooperate with the main body to hold an insertion part of the endoscope or an operation part connected to the insertion part.内視鏡のチャンネルに対して挿通される挿入体を有する処置具の、前記チャンネルに対する移動を補助する補助具は、前記処置具を挿通する挿通路を形成する可撓部と、前記可撓部に設けられ、前記チャンネルと前記挿通路とを連通させるように前記内視鏡に連結可能な連結部と、前記可撓部に設けられ、第1ジョイントを有する本体と、前記第1ジョイントに着脱可能に接続される第2ジョイントを有し、前記本体と協働して前記内視鏡の挿入部又は前記挿入部に接続された操作部を保持する保持体とを備える。
