PURPOSE: To provide an electric discharge processing device which removes the influence of the electrostatic capacitance produced on a feeder cable for high speed processing in the inter-electrode part and/or between electrode and the work to be processed, performs a stable specular processing lying under a specific roughness, and ensures great improvement of the performance associate with the costs.

CONSTITUTION: Thiis device(s) includes a power supply 20 for high speed processing which supplies a high peak current, an AC high frequency power supply 11a which generates an AC high frequency wave of 7-30MHz, a matching circuit 12a to perform impedance matching for the processing gap during discharging, and a low capacitance feeder cable 18 for AC high frequency processing and a low inductance feeder cable 19 for high speed processing connected directly between electrode and a work to be processed. An AC high frequency current of 7-30MHz is supplied from the low capacitance feeder cable 18 in the condition that the impednace matching is made for the processing gap during discharging at the stage of finish processing, and thereby the processing is carried out in such a manner that the electrostatic energy of the low inductance feeder cable 19 will not be released to inter-electrode space.