PURPOSE: To increase the processing effect by utilizing a pulse electrolytic operation while generating supersonic vibrations.

CONSTITUTION: This is processing device for electrolytically grinding a work 3 while supplying an electrolyte between a tool electrode 1 and the work 3 through an ejection bore 5 and applying an electric current thereto. This device is provided with a vibrator 4 for applying supersonic vibrations to the tool electrode 1, and a processing power source 6 for applying to the electrolyte a processing pulse of a pulse width of not more that 100μS, preferably, not more than 50μS. Owing to a combined operation of the vibrator 4 and processing power source 6, the work 3 can be processed stably without any arc discharge so that the processing rate can be increased.