A treatment tool comprising, a probe including a first surface that carries out incision of the living tissue with the ultrasonic vibrations, a second surface that carries out coagulation of the living tissue, and an insulation portion that covers the first surface, and a jaw which is engageable with the probe and disengageable from the probe, the jaw including a third surface facing the first surface in an engaging state and a fourth surface facing the second surface in the engaging state.
