PURPOSE:To avoid the change of the electrostatic capacity of a photoreceptor due to the repetitive use and to prevent the fluctuation of the charging potential, by performing the irradiation for destaticization with the 1st peak wavelength light and then with the 2nd peak wavelength light of different wavelength and at the same time superposing both lights on each other at least at a part of them. CONSTITUTION:The 1st and 2nd destaticizers 8 and 9 are provided at the positions near the circumference surface of a photoreceptor drum 1 provided between a cleaning device 7 and a charger 2. The destaticizer 8 emits the light having a >=6,000Angstrom peak wavelength to give an exposure over the entire region in the width direction of the drum 1 with a proper width secured in the circumference direction. The 2nd destaticizer 9 emits the light having a <=6,000Angstrom peak wavelength to perform an exposure like the destaticizer 8. These two lights superpose at the end part in the width direction which is the circumferential direction of the drum 1.