<p>An earth electrode member such as an earth roller in contact is disposed on the upstream side of a form transfer roller for secondary transfer on a form from an intermediate transfer belt. The earth contact width of the earth roller brought into contact with the belt is narrower than the belt contact width of the form transfer roller. The leak current flowing to the intermediate transfer belt through the contact portion with which the form transfer roller comes in direct contact is suppressed because the size of the form is small. A secondary transfer voltage applied to the form transfer roller and a backup roller is changed by means of a pole-changing switch circuit when conducting cleaning, thereby applying transfer voltages for transfer and cleaning by a single power supply.</p>
