First and second switching regions include first and second gate electrodes respectively. Channel currents of the first and second switching regions are controlled according to electric charge amounts supplied by control signals input to the first and second gate electrodes respectively. The second switching region is connected in parallel with the first switching region. A control section outputs a first control signal for turning-on the first switching region to the first gate electrode and a second control signal for turning-on the second switching region to the second gate electrode. The control section stops outputting the second control signal after a first predetermined period elapses from a start of outputting the first and second control signals, and outputs the second control signal after a second predetermined period elapses from a stop of outputting the second control signal.