Abstract: A driving device for a rotor blade of a wind turbine has an asynchronous machine (6) for adjusting the rotor blade, an electrically operable brake (5) disposed at the driving unit for fixing or braking the driving unit and an electrical supplying device (2), via which the asynchronous machine is connectable with a three-phase power supply network. The supplying device comprises a rectifier (21), an inverted rectifier (23) and a direct-voltage intermediate circuit. A direct-voltage regulator (24) is provided which is connected with the intermediate circuit, via which the brake is electrically supplied. By supplying the brake by the intermediate circuit, an additional voltage source for the brake can be spared and the brake can be implemented extremely simply.