Provided is an advancing and retracting aid for a treatment tool capable of improving workability of an operator and an assistant while preventing breakage or the like of a treatment instrument. The assisting tool for assisting the movement of the treatment instrument is a flexible instrument having an insertion path (58) for inserting the treatment instrument (13) inserted into the channel in the insertion section (17) of the endoscope (12) A pipe (55) connected to the flexible tube (55) and having a curved part in the middle of its entire length, a pipe having a passageway (58) for the treatment instrument (13) formed by a rigid pipe line A connecting member (45) connected to the pipe member (62) and formed so as to connect the channel and the insertion path (58) of the pipe member (62) A holding section (56) for holding the operation section (16) of the endoscope (12) which is attached to the flexible tube (55) and is connected to the insertion section (17) or the insertion section (17) of the endoscope ).処置具の折れ等を防止しつつ、術者および補助者の作業性が良好にできる処置具の進退補助具を提供する。 処置具の移動を補助する補助具は、内視鏡(12)の挿入部(17)におけるチャンネルに挿入される処置具(13)を挿通するための挿通路(58)が形成された可撓管(55)と、可撓管(55)に接続されるとともに、全長の途中で湾曲した部分を有し、剛体の管路により処置具(13)の挿通路(58)が形成された管路部材(62)と、管路部材(62)に接続されるとともに、前記チャンネルと管路部材(62)の挿通路(58)とが連結するように形成された連結部(45)と、可撓管(55)に装着され、内視鏡(12)の挿入部(17)または挿入部(17)と接続する内視鏡(12)の操作部(16)を保持する保持部(56)と、を備える。
