Abstract: The invention relates to a ballast for operating electric lamps, having an inverter (WR), a DC voltage supply circuit (GLV) for the inverter (WR), a load circuit, connected to the inverter (WR), for supplying voltage to one or more electric lamps (LP), a microcontroller (MC) for monitoring and controlling the operation of the ballast and a voltage supply device (HLV) for the microcontroller (MC). According to the invention, the voltage supply device (HLV) is designed as a DC-DC converter—in particular as a step-down converter—, which ensures a voltage supply to the microcontroller (MC) even in the standby mode of the ballast with the inverter (WR) deactivated. As a result, the power consumption in the standby mode can be reduced to less than 0.5 W.