PURPOSE: To facilitate exchanging of cutting tools and grinding thereof in a method wherein, at the end of a flexible vibrator driven by a vibrator, the holder fixed the tool is placed at the loop part of vibration and is clamped by a clamping tool.

CONSTITUTION: A deflection vibrator 10 is provided via two electrode plates 17 and 18, with the electrodes thereof made opposite to each other by electrostrictive elements 13 and 14 chucked between metal members 11 and 12 and polarized in a thickness direction. Also, an insulation pipe 19 is inserted along the internal surfaces of the elements 13 and 14 and a common electrode 20 is provided between the element 14 and the metal member 12. When negative- phase voltage is applied to said electrodes 17 and 18 for driving the deflection vibrator 10, a cutting tool 26 vibrates in a vertical direction. And when a tightened ring 28 vibrates at a loop position L1, the amplitude of the cutting tool 26 becomes large, thereby enabling proper vibration cutting. Then, a vibration velocity gives a rise due to an increase in equivalent mass from the cutting edge of the cutting tool 16 to the loop L1, and vibration inertia also becomes large, thereby enabling all the more proper vibration cutting.