A driving method is provided which improves the duty ratio, which presents high image quality by securing a sufficient length of sustain (lighting) period when gray scales are increased in number, and which prolongs the lifetime of a light emitting element. One frame period has m (m is a natural number equal to or larger than 2) different sub-frame periods SF.sub.1, SF.sub.2, . . . , and SF.sub.m. The m different sub-frame periods SF.sub.1, SF.sub.2, . . . , and SF.sub.m each have an address period and a sustain period. Analog data signals are inputted to their respective light emitting elements in the address period. In the sustain period, the light emitting elements emit light in response to the analog data signals at n (n is a natural number equal to or larger than 2) levels of luminance for gray scale display.