DC power supply device

Provided is a direct current power supply device, with which it is possible to apply a positive voltage and eliminate arc discharge, and to reliably suppress recurrences of arc discharge after said elimination thereof when normal operation is restored. The direct current power supply device comprises: a direct current power supply unit that injects electricity into a target; an arc sensor unit; a first switching element (SW1) disposed in series with the negative output; a second switching element (SW2) and an inverse voltage application unit that applies inverse voltage, which are disposed in parallel between the positive and negative outputs; and a control means (4). During normal operation, electricity is transmitted by the first switching element to the electrodes in a state wherein the application of inverse voltage from the inverse voltage application unit to the electrodes is interrupted by the second switching element. If an arc discharge is detected, inverse voltage electricity is transmitted to the electrodes by the second switching element from the inverse voltage application unit and applied over a prescribed interval. After said interval has elapsed, the transmission of electricity to the electrodes is cut off by the first switching element for a prescribed interval. The transmission of electricity to the electrodes recommences thereafter.