PURPOSE: To attempt an improvement of grinding efficiency in electrolytic grinding work method applied to hard-to-grind materials by applying high frequency or pulse voltage between a conductive grinding stone and a work piece with electrolyte injected whereby moving the grinding stone for grinding.

CONSTITUTION: Both electrodes of a power source 14 are connected with a grinding stone 1 and a conductive work piece 13 through a slip ring 5 and a grinding stone shaft whereby high frequency or pulse voltage is applied. Simultaneously, the grinding stone 1 is rotated or swung at high speed whereby electrolyte 6 is injected onto the grinding stone 1 and the surface to be worked through a nozzle 7 by means of a pump 12. Owing to this constitution, slight melt takes place over the surface of the work piece 13 due to electrodes and discharging, and simultaneously the molten portion is mechanically peeled off and removed by abrasive grains 4. As both electrical grinding and mechanical grinding are performed simultaneously on the work piece 13 by this electrolytic grinding work method, highly efficient grinding can be made possible. Moreover, electric discharging is useful to prevent grinding stones from being loaded.