A switching device for low or medium voltage electric power distribution networks, the switching device including one or more electric poles and, for each electric pole: an insulating housing defining an internal volume of said electric pole; a first pole terminal and a second pole terminal electrically connectable with a corresponding electric phase conductor of an electric source and with a corresponding electric phase conductor of an electric load, respectively; a movable contact and a fixed contact, which are coupleable/decoupleable one to another, the fixed contact being electric connected with the first pole terminal, the movable contact being electrically connected with the second pole terminal; a stack of semiconductor devices adapted to switch in conduction state or in an interdiction state depending on the voltage provided thereto.