PURPOSE: To obtain a small-sized cutting/grinding device which generates little noise and permits high efficiency by constituting the device from a case into which a super- megnetostriction member and an exciting coil are accommodated and one edge of the super- magnetostriction member is fixed and a vibration amplifying/transmission mechanism for amplifying and transmitting the extension/contraction vibration of the super-magnetostriction member to a working tool from the free edge.

CONSTITUTION: Under the action of a bias magnetic field due to a permanent magnet 3, an electric power is supplied into an exciting coil 4 from an ac power source 5, and then a super-magnetostriction member 1 is extension/contraction-vibrated according to the direction of the acting magnetic field by the ac magnetic field, and since, in this case, one edge 1a of the super-magnetostriction member 1 is fixed on a casing 6, and free edge 1b performs the vibration for the advance and retreat in the axial direction. The upper edge of a tool installation rod 7 installed at the free edge through a connecting member 9 vibrates in reciprocation around a supporting pin 12, and also the tool fixed edge vibrates in reciprocation, and working is carried out by a tool 8. Since, in this case, the axis supporting pin 12 is installed at the position close to the connection part for the super-magnetostriction member in comparison with the tool fixed edge, the vibration of the free edge of the super- magnetostriction member is amplified by the lever action, and cutting is carried out, applying the amplified vibration movement to the tool 8, and working such as polishing can be carried out.