A bipolar high-frequency treatment tool for an endoscope comprising a flexible sheath having a multi-lumen tube which is rotatable about an axis of the flexible sheath and is formed to have a pair of guide lumens, a pair of high-frequency electrodes which are arranged to be movable at a tip end of the flexible sheath and are adapted to be electrically insulated from each other, a pair of operating wires which are made of an electrically conductive material but are adapted to be electrically insulated from each other, wherein each of the pair of operating wires is respectively arranged in each of the guide lumens, and wherein the pair of high-frequency electrodes is rotated as the pair of operating wires is rotated and as the multi-lumen tube is rotated about the axis of the flexible sheath accordingly, is provided.