A configuration in which a voltage (a gate on voltage) of only one system is used as a voltage for turning scanning lines to a selected state is employed (single power supply system configuration). A unit circuit that constitutes a shift register within a gate driver includes a thin film transistor whose source terminal is connected to an output control node. In such a configuration, when the external power supply is stopped, a voltage supplied to a gate terminal of the thin film transistor and a voltage supplied to a drain terminal of the thin film transistor are set to the gate on voltage.