PURPOSE: To make it possible to facilitate the cleaning of an apertured electrode body by a constitution wherein the apertured electrode body and a rear surface electrode roller can easily be separated from each other.

CONSTITUTION: On a main body case 30 side, an apertured electrode body 1, a toner feeding device 10, a fixing device 26, main power source 34 and a main board 35 are provided, while a rear surface electrode roller 22 is provided on a lid member 31. Under the condition that the lid member 31 is closed, the apertured electrode body 1 and the rear surface electrode roller 22 are held so as to have the interval of 1mm between them. Under the condition that the lid member 31 is opened, the apertured electrode body 1 and the rear surface electrode roller 22 are fully separated from each other.