Provided is a power supply apparatus which can effectively restrict the current rise at the time of occurrence of arc discharge that is directly related to the occurrence of splashes or particles, and which is also capable of preventing the discharge voltage from getting excessive at the time of finishing the arc processing. The power supply apparatus has: a DC power supply unit which applies a DC voltage to a target which comes into contact with a plasma; and an arc processing unit which can detect arc discharge generated in the electrode by positive and negative outputs from the DC power supply unit, and also which can perform arc discharge suppression processing. An output characteristics switching circuit switches the outputs such that the output to the electrode has constant-current characteristics and that the output to the electrode has constant-voltage characteristics by the time of completion of the arc suppressing processing.