An ultrasound probe includes a probe body, and a treatment unit. The treatment unit includes: a cutter that is provided at a distal end part of the treatment unit and that cuts the bone according to move of the treatment unit along a longitudinal axis in a state where ultrasonic vibration is being transmitted to the probe body; and a path that is provided in the treatment unit and through which debris of a bone that is cut by the cutter are discharged along the longitudinal axis toward a proximal end side with respect to the cutter. The path includes a first opening that is provided in a distal end surface of the cutter; and a second opening that is provided in a side surface part of the treatment unit, wherein the path allows the first opening and the second opening to communicate.