PURPOSE: To obtain a photoreceptor having excellent photosensitive characteristics and durability in the stage of giving electrostatic charging hysteresis to the photoreceptor by application of an AC voltage by irradiating light simultaneously thereto when the voltage of the polarity at which majority carriers are not implanted is applied to the photoreceptor.

CONSTITUTION: A positive charger 2 and a negative charger 3 for applying voltages around a photosensitive drum 1 produced by providing a phoroconductive layer on a conductive substrate and a halogen lamp 4 is contained in the charger 3 for applying the voltage of the polarity at which the majority carriers of the photosensitive layer are not implanted. The drum 1 is disposed in an outside box 7. A driving motor 6 is driven to rotate the drum 1 and a high voltage transformer 5 is operated to apply a high voltage upon the drum 1. At the voltage of the polarity at which the majority of the carriers of the photosensitive layer are implanted, the photoreceptor 1 is subjected to an electrostatic charging hysteresis treatment, and at the voltage of the reverse polarity, light is irradiated to decrease the resistance of the photoreceptor so that said treatment is not effected.