Switching device

a b a a b b To provide a switching device capable of a switch-controlling a voltage source regardless of voltage changes in the voltage source to be switched and the voltage source employed for switch control.A switching path includes, between the input terminal and output terminal for a voltage source, a series connection of the source or drain electrodes of PMOS transistors and connected to their back-gate electrode. A driving circuit has an NMOS transistor having a load resistor at its drain electrode and NMOS transistor having a load resistor at its drain electrode, which are connected to the gate electrodes of the PMOS transistors, respectively and receives the output from the logic inverter for the switching control.