PURPOSE: To stabilize the electrifying capacity for a long period of time by providing a wire moving member on a corona electrifying device consisting of an electrode use conductive wire for applying a high voltage and a shielding plate, exposing an undischarged part of the wire at the time of moving the overall length of the wire, and bringing a cleaning member into slide-contact with the part of the wire.

CONSTITUTION: At the time of moving an electrode wire 11, while bringing it into slide-contact with total four pieces of rollers 12 of two pieces each of the upper and the lower parts, respectively, it is moved by using a moving member 13 to which both ends of the wire 11 are fixed. In this case, a high voltage to the wire 11 is applied from a high voltage power source 14 through the rollers 12, corona discharge is executed by the wire part surrounded by a shielding plate 15, and charge is electrified to a rotary photosensitive body 16 provided thereon. In such a way, at the time of bringing the wire 11 to reciprocating motion by the moving member 13, the wire 11 can be exposed on the reverse side opposed to the photosensitive body 16, and during this time, wiping-out by a cleaning member can be executed.