first vibrating portion of the ultrasonic transmission unit is provided on the first vibration body portion, and a proximal-side relay unit which is located which is one relay antinode positions of the first antinode position. The second vibrating part, said continuous with first the proximal-side relay portion of the vibrating portion, or the second vibrating body portion in contact with the state on the base end side relay portion of the first vibrating part provided, the distal side relay unit located at different intermediate position and the second loop position and a second nodal positions, the proximal end of the second vibrating portion is located, in contact with said first vibration section without this, provided with a non-contact vibration portion which extends in the proximal direction side of the distal-side relay unit.超音波伝達ユニットの第1の振動部は、第1の振動本体部に設けられ、第1の腹位置の1つである中継腹位置に位置する基端側中継部を備える。第2の振動部は、前記第1の振動部の前記基端側中継部と連続する、又は、前記第1の振動部の前記基端側中継部に当接する状態で第2の振動本体部に設けられ、第2の腹位置及び第2の節位置とは異なる中途位置に位置する先端側中継部と、前記第2の振動部の基端が位置し、前記第1の振動部と接触しない状態で、前記先端側中継部より基端方向側に延設される非接触振動部と、を備える。
