The treatment tool is directed to a proximal probe for transmitting ultrasonic vibration from the ultrasonic transducer from the proximal end portion to the distal end portion and a treatment portion having ultrasonic vibration from the proximal end portion to the distal end portion. And transmitting the vibration from the ultrasonic transducer to the proximal end of the proximal probe by abutting the proximal end of the distal probe on the distal end of the proximal probe A holding portion that holds a state that can be transmitted from the portion to the tip portion of the tip side probe, and an operation that is provided in the holding portion and rotates around the center axis of the tip side probe and the base end side probe, An operation unit that rotates the distal probe around the axis of the central axis relative to the proximal probe to direct the treatment section at the distal end of the distal probe in a desired direction. 処置具は、超音波振動子からの超音波振動がその基端部から先端部に向かって伝達される基端側プローブと、超音波振動をその基端部から先端部に有する処置部に向かって伝達可能な先端側プローブと、前記基端側プローブの前記先端部に前記先端側プローブの前記基端部を突き当てて前記超音波振動子からの振動を前記基端側プローブの前記基端部から前記先端側プローブの前記先端部に伝達可能な状態を保持する保持部と、前記保持部に設けられ、前記先端側プローブ及び基端側プローブの中心軸の軸回りに回転させる操作により、前記基端側プローブに対して相対的に前記先端側プローブを前記中心軸の軸回りに回動させ前記先端側プローブの先端部の前記処置部を所望の方向を向かせる操作部とを有する。
