An electric discharge machining apparatus includes: electrodes the total quantity of which is equal to N; an alternating-current power source; and capacitors the total quantity of which is equal to N. The alternating-current power source applies an alternating voltage commonly to the electrodes. One end of each of the capacitors is connected to a corresponding one of the electrodes, whereas the other ends of the capacitors are commonly connected to the alternating-current power source.

An electric discharge machining apparatus includes a power supply, an electrode gap formed from an electrode and a workpiece, a current limiting resistor connected between the power supply and the electrode gap, switching elements that turns on and off application of a voltage from the power supply to the electrode gap, an inductance element connected in series between the switching elements and the electrode gap, and a control unit that controls the switching elements. The control unit causes the switching elements to perform ON/OFF operations according to a switching pattern having an on-pulse time width (Ton) in which a voltage of the electrode gap can reach a voltage value of the power supply in an on-pulse time and a pause time width (Toff) equal to or longer than a time width (tic) of a discharge current flowing during the capacitor discharge and shorter than a cycle (Tso) of the self-excited oscillation.