A switching device includes an energy store and a measuring device connected to a control apparatus. The energy store is connected in series between the supply connection and the power supply. The control apparatus can monitor the energy supply of the switching device in the area between the supply connection and the power supply taking place via the supply connection via the measuring device. If the energy supply monitored by the measuring device falls into a critical range, and using the energy from the energy store: the control apparatus connects the semiconductor switch in an electrically conductive manner and then opens the second switch; and subsequently switches the semiconductor switch to an electrically non-conductive state and then opens the first switch.