The ultrasonic probe for a shoulder joint includes a curved extending portion that curves with respect to the probe main body portion toward a first intersecting direction that intersects the longitudinal axis. The curved extending portion includes a first curved outer surface facing the first intersecting direction, a second curved outer surface facing the second intersecting direction opposite to the first intersecting direction, A third width outer surface facing the first width direction and the first width direction side perpendicular to the first cross direction and the second cross direction； and a second opposite to the first width direction A fourth curved outer surface facing the width direction side. The relay groove of the cutting surface formed on the second curved outer surface includes the extended groove of the cutting surface formed on the third curved outer surface and the cutting formed on the fourth curved outer surface. It is continuous with the extended groove on the surface.肩関節用の超音波プローブは、長手軸に交差する第１の交差方向側へプローブ本体部に対して湾曲する湾曲延設部を備える。前記湾曲延設部は、前記第１の交差方向側を向く第１の湾曲外表面と、前記第１の交差方向とは反対の第２の交差方向側を向く第２の湾曲外表面と、前記第１の交差方向及び前記第２の交差方向に垂直な第１の幅方向第１の幅方向側を向く第３の湾曲外表面と、前記第１の幅方向とは反対の第２の幅方向側を向く第４の湾曲外表面と、を備える。前記第２の湾曲外表面に形成される切削面の中継溝は、前記第３の湾曲外表面に形成される切削面の延設溝、及び、前記第４の湾曲外表面に形成される切削面の延設溝と連続する。
