PURPOSE: To grind quickly a high precision lens, which is designed for special use and has small diameter and small radius of curvature, by performing the grinding while the lens material in motion of braying miso at a low speed is pressed against a grinding dish, which is vibrating finely at a high speed in the circumferential direction.

CONSTITUTION: In order to grind a lens material, a drinding dish 3 provided with a radius of curvature into which the grinding is proposed is installed on a grinding shaft 2. A lens holder plate 15 on which the lens material L is mounted is installed at a piston rod 14 of a slide shaft 11, and the lens material L is pressed against the grinding dish 3 by means of air in an air cylinder part 12. Thereafter vibration is begun at a vibrator 4 with a vibrating device 7 by operating a drive motor 16 and an oscillator 7, and the grinding shaft 2 advances and retracts in the circumferential direction, so that the grinding dish 3 makes fine vibration at a high speed. A rotary shaft 9 and a slide shaft 11, on the other hand, are put in motion of braying miso by the drive motor 16, and the lens material L at its lower cost makes a revolutional motion at a low speed to undergo the grinding process.