There is provided a charging device having high durability, of which controllability of charged potential of a photoreceptor is hardly impaired even with a some amount of contaminants such as a toner so that control of charged potential of a photoreceptor can be stably carried out to fall in an appropriate range over a long period of time, and moreover which is inexpensive. As a grid electrode, one prepared by forming a composite plated layer composed of three layers of an Sn plated layer, an Sn—Co plated layer and a Ni plated layer is used. More preferably, an upper layer is an Sn plated layer, an intermediate layer is an Sn—Co plated layer and a lower layer is a Ni plated layer.