The invention concerns a device for supplying direct charging current (CHj) to an arc furnace. The device comprises at least a transformer (28, 29) powered at its primary coil with a three-phase alternating current, a rectifier (RDi) for delivering a rectified voltage and a rectified current and dc-to-dc converter means controlled by a current setpoint (Irefj) and placed between the output of at least a rectifier and the charge (CHj). The direct current Ichj supplying the charge is represented by the formula Ichj = Pref/Vchj, wherein: Pref is a substantially constant physical quantity and Vchj is the value of the voltage measured at the terminal of the charge (CHj). The invention is applicable in the field of steel production.