Image forming apparatus

An image forming apparatus includes an image bearing member, a charging member for charging the image bearing member, an exposure unit for exposing the charged surface of the image bearing member, a developing apparatus that supplies a developer containing a toner particle and an external additive having an opposite charging polarity to the regular charging polarity of the toner particle to the image bearing member, a cleaning member for removing the developer from the image bearing member, a transfer member for transferring a developer image on the image bearing member onto a transfer subject material, and a voltage application unit for applying a voltage to the transfer member. During an image non-formation period as a lubrication operation to the cleaning member, (i) the developer is supplied to the image bearing member, and (ii) a voltage having an identical polarity to a voltage applied during the image formation operation is applied.