The present invention provides a display device having a driving transistor for current-driving a light-emitting element provided in each pixel, wherein the drain of the driving transistor is connected to a first power source, the source of the driving transistor is connected to the light-emitting element and one end of a capacitor, and the gate of the driving transistor is connected to a voltage source via a first switch and simultaneously therewith is connected to the other end of the capacitor via a second switch; the other end of the capacitor is further connected to a signal line via a third switch; and the display device has a control circuit for selectively controlling the first power source to a plurality of voltages.