Abstract: The device according to the invention offers the advantage that by means of at least two drive positions and a neutral position of a planetary gear as a drive transmission for an electric machine, this electric machine can be used both as a starter for starting the internal combustion engine and as a generator for supplying power to an electrical system of the motor vehicle. The disposition of the electric machine connected in series with the planetary gear, for example in the drivetrain of the motor vehicle between a coupling and a manually shifted transmission preferably on a transmission input shaft, in particular has the advantage that the electric machine can remain in constant engagement without expensive devices for meshing and demeshing a conventional starter, and a control of the planetary gear based on fixed parameters can be carried out simply by means of the motor control.