A vibrating cutting tool capable of making uniform micro-vibrations at the cutter edge generated during machining. The vibrations at the cutter edge are transmitted to balls biassed by springs, compressing the springs. The vibrations are transmitted from the balls through the output shaft back to the cutter edge. While the cutting force is small, the amplitude of vibration of balls is relatively large. When it increases, the holder acts on the balls more than the spring does so that vibration is suppressed. As a result, the amplitude of vibration becomes uniform.
