This treatment tool, treatment tool that is inserted through the treatment instrument channel of an endoscope A is a flexible elongate longitudinal shaft member having a rotation guide portion positioned on the curved portion and a curved portion protruding from the opening of the distal end of the treatment instrument channel, a treatment section provided at the distal end of the longitudinal member , it provided a. Curvature direction of the rotation guide portion and the curved direction of the curved portion is opposite to each other.この処置具は、内視鏡の処置具チャンネルに挿通される処置具であって、処置具チャンネルの先端の開口から突出する湾曲部位及び湾曲部内に位置する回転誘導部を有する可撓性の細長い長軸部材と、長軸部材の先端部に設けられた処置部と、を備える。湾曲部位の湾曲の向きと回転誘導部の湾曲の向きは、互いに逆向きである。
