Abstract: A plasma display adopting a sub-field scheme drive, which seeks to reduce light intensity level variation when the input video signal field frequency is varied. A sub-field setter 2 sets a plurality of sub-fields from the 1-st one (SF1) to an n-th one (SFn) with light intensity level ratios of 2.sup.n-1 :2.sup.n-2, . . . , 2:1. A sustained discharge pulse number controller 3 generates sustained discharge pulses for sustained light emission. The sustained discharge pulses are generated in numbers, which correspond to the relative light intensity levels of the individual sub-fields, and are controlled according to the rate of change in the input video signal field frequency from a reference field frequency.