The invention relates to a method for operating a rotating electric machine, wherein the rotating electric machine is connected by phases to a converter circuit having a direct-current circuit for switching at least two voltage levels, and the phases of the converter circuit are connected to the direct-current circuit according to a selected switch state combination of switch states of power semi-conductor switches of the converter circuit. In order to reduce the switching frequency of the power semi-conductor switches, a prediction is made on the further behavior of the overall system, and subsequently the optimum switching state combination is selected based on the preceding selected switching state combination and with regard to the number of transitions from the preceding selected switching state combination to the selected switching state combination and with regard to the respective predetermined value range for the torque of the rotating electric machine, for the magnetic stator flow of the rotating electric machine, and for the potential on the partial connection. The steps are carried out by means of a digital signal processor, and by means of a field programmable gate array (FPGA).