A high-frequency treatment tool for an endoscope including a flexible sheath being made of electrically insulating material to be inserted through an insertion channel of the endoscope, a conductive operation wire, which is adapted to be advanced and retracted inside the flexible sheath, and a partially elongated electrode being arranged at a distal end of the high-frequency treatment tool separately from the operation wire, to which high-frequency electrical current is supplied for high-frequency treatment, is provided. The electrode is adapted to be protruded and retracted in an axial direction thereof from the distal end of the high-frequency treatment tool by an operation to the operation wire. The electrode is allowed to be removed from the high-frequency treatment tool independently from the operation wire.