In a display device including a pixel in which a driving transistor and a light-emitting element connected to a source of the driving transistor are provided, a display defect is suppressed. Before a period in which the driving transistor supplies a current to the light-emitting element, a voltage which has substantially the same level as a voltage which is applied to one electrode and the other electrode of a capacitor is kept as a voltage between a gate and the source of the driving transistor in the period. Specifically, a node where the one electrode of the capacitor and the gate of the driving transistor are electrically connected to each other in the period is made in a floating state, and the other electrode of the capacitor and the source of the driving transistor are electrically connected to each other.