A switching device for conducting and interrupting electric currents, has a first mechanical contact assembly, a semiconductor switch, which is connected in parallel with the first mechanical contact assembly; a second mechanical contact assembly, which is connected in series with the first mechanical contact assembly; an auxiliary coil, which is galvanically isolated from the circuit of a switching drive for moving contacts of the first and second mechanical contact assemblies and is electromagnetically coupled to a coil of the switching drive in such a way that a voltage is produced in the auxiliary coil when the voltage supply of the switching drive is switched off; and switching electronics, which are designed to switch the semiconductor switch on and off and which are supplied by the voltage produced in the auxiliary coil when the voltage supply of the switching drive is switched off.