To provide a novel driving method for driving an electronic device by using digital gray scale and time gray scale in combination, which secures high duty ratio, which can display an image normally even when a sustain period is shorter than an address period, and which is hardly affected by dulled signal waveform. In a sub-frame period (102) where a sustain period is shorter than an address period, a clear period (105) is squeezed in between completion of a sustain period (104) and start of an address period of the subsequent sub-frame period. The length of the sustain period (104) thus can be set without being limited by the length of an address period (103). This non-display period is provided by changing the electric potential of a storage capacitor line. Therefore, unlike the case where the non-display period is provided by changing the electric potential of a cathode wiring, the present invention is hardly affected by dulled signal waveform.