The present invention provides a plasma display driving device capable of enhancing contrast by adjusting in accordance with the ambient illuminance of a plasma display panel the level change rate at the leading edge portion of a resetting pulse for causing the occurrence of a resetting discharge, which initializes all the discharge cells of the plasma display panel. The present invention also provides a plasma display panel driving method for enabling power consumption to be held in check by changing the number of sustaining pulses per unit time to be applied to each discharge cell in an emission sustaining step in accordance with the ambient illuminance of the plasma display panel, and, in addition, by adjusting the pulse width of at the least one of the above-mentioned sustaining pulse and scanning pulse for pixel data writing. The present invention also provides a plasma display panel driving device that enables power consumption to be held in check by determining a frequency of application of a displaying pulse to be applied per unit time based on the average brightness of an input image and the illuminance around a PDP, and by applying displaying pulses to each discharge cell in accordance with the frequency of the application.