PURPOSE: To increase the output of vibration by fitting ≥2 electromagnetic in the circumferential direction of inner wall of a casing so that the magnetic flux is directed in the axial direction of the casing and supporting a vibrator having a permanent magnet by a plate spring so as to vibrate the oscillator in the thrust direction.

CONSTITUTION: In the circumferential direction of the inner wall of the casing 21, ≥2 electromagnets are fitted. An opening section of a yoke 22 having a channel shaped cross section of the electromagnets is directed in the direction of a shaft 24 of the casing 21, a coil 23 is inserted to the inside, so as to make the magnetic flux in parallel with the shaft 24 between magnetic poles 22a, 22b. Both ends of the shaft 24 of the vibrator having a moving mass 28 are supported freely vibratorily by disc springs 25, 25 fixed to the casing 21. Plural permanent magnets 26 are fitted among magnetic path forming yokes 27a∼27c at a nearly center part of the shaft 24 and at a position corresponding to the magnetic poles 22a, 22b of the electromagnets so that the opposite poles of the permanent magnets 26 are in contact with each other. In energizing the electromagnets by an AC power, the magnetic poles 22a, 22b produce N and S poles alternately and repeat adsorption and repulsion with the permanent magnets 26. Moreover, the center of vibration of the springs 25 and the center of gravity of the shaft 24 are made coincident with each other and efficient vibration is produced.