An arc furnace power supply device with a rectifier is specified, which rectifier on its alternating voltage side can be connected with an electrical alternating voltage supply network and on its direct voltage side is connected with a direct voltage circuit. Moreover the arc furnace power supply device comprises an inverter, which inverter on its direct voltage side is connected with the direct voltage circuit and on its alternating voltage side with at least one arc electrode. For improvement of the stability and even burning of the arc the inverter is configured as an inverter that applies a rectangular alternating voltage to the arc electrode.