A treatment tool for an endoscope includes a sheath which is extended along a longitudinal axis； a pre-curved portion which is disposed at a distal portion of the sheath； a knife wire lumen which is formed along the longitudinal axis of the sheath； a first communication hole and a second communication hole which are open on an outer circumferential surface to communicate the outer circumferential surface positioned with the knife wire lumen； a wire-shaped cutting portion which is protruded from the first communication hole and the second communication hole, and is extended in a position spaced from the outer circumferential surface and the virtual plane； a fixing portion which is provided to fix an end portion of a wire connected to the cutting portion inside the knife wire lumen, and a bending portion which is provided to bend the wire.
