Switching device comprising: a switching unit comprising, for each electric pole, a first disconnection contact, a second disconnection contact and one or more solid state switches; a supporting frame comprising, for each electric pole, a third disconnection contact and a fourth disconnection contact, which are coupled/separated respectively with/from the first and second disconnection contacts, when the switching unit is in an insertion/withdrawn position with respect to the supporting frame; actuating means for moving the switching unit between the insertion position and said the withdrawn position, and viceversa; a control unit comprising control means that are configured to coordinate the operation of the actuating means and the solid state switches, when an insertion/withdrawn operation of the switching unit has to be performed, so that the actuating means move the switching unit only when the solid state switches are in an off-state.