In display device comprising a reflection element whose display state is changed by the application of the electric field, and a photoconductive layer whose conductivity is changed by the application of light, a drive voltage is applied to the reflection element and the photoconductive layer, and writing light is applied selectively to the photoconductive layer, whereby the electric field to be applied to the reflection element in a region where the writing light has been applied is changed, and when a prescribed image is written in the reflection element, the writing light is applied after the photoconductive layer is charged for a prescribed charging period of time. Thus, the print concentration can be stabilized, and the contrast can be improved.