A power supply device for plasma processing, wherein electric arcs may occur, comprises a power supply circuit (10) for generating a voltage across output terminals (1, 2), and a first switch (25) connected between the power supply circuit and one (1) of the output terminals. According to a first aspect the power supply device comprises a recovery energy circuit (40) connected to the output terminals (1, 2) and to the power supply circuit (10). According to a second aspect the power supply device comprises an inductor (21) connected between the power supply circuit (10) and one (1) of the output terminals (1, 2), and a second switch (22) connected parallel to the inductor (21). According to a third aspect the power supply device comprises a controller (60) for controlling the power supply circuit (10) and the first switch (25). The controller (60) is configured to determine at least one delay parameter by means of a self-adaptive process.