PURPOSE: To improve a cutting efficiency by incorporating an ultrasonic wave generation device and a horn transmitting an ultrasonic vibration in a hand piece, providing a saw fitting part at the horn tip part and fitting the saw thereto via a spurious vibration restraint plate.

CONSTITUTION: An ultrasonic wave generation device 1 pinches a piezoelectric vibrator consisting of two piezoelectric bodies 2 and three piezoelectric bodies 3 by a horn 4 and load measure 5, is tightened by a bolt 6 and nut 7 and incorporated inside a hand piece 10. On the horn 4 transmitting a ultrasonic vibration an engagement part 4a formed with a knurling tool is provided and engaged with the inner peripheral face of the hand piece 10. There is a fitting screw part 4b in which a saw fitting part 12 is screwed at the tip part of the horn 4, on the saw fitting part 12 a recessed part 12a is formed in the axial direction and to the recessed part 12a the base end part of a saw 13 is inserted and fixed via a spurious vibration restraint plate 14. The cutting efficiency is, thus improved because of no spurious vibration being caused and the cut face becomes a smooth finishing.