A plasma display device comprises an area ratio detection means for detecting the area ratio of pixels having any luminance higher than a predetermined value in a display region; and a sustain frequency adjust means for adjusting, in accordance with the detected area ratio, the frequency or number of sustain pulses inputted to paired sustain electrodes in such a manner that the luminance in the display region satisfies a predetermined reference value. In this device, the frequency or number of the sustain pulses inputted to the paired sustain electrodes is adjusted in accordance with the detected area ratio, so that the luminance is always corrected to the reference value to thereby achieve proper expression of preset gradations.