An image forming apparatus includes a conveyance section, an image forming section, a fixing section, a sheet output tray, a toner container, a suitable product determining section, and a control section. The suitable product determining section determines whether the toner container loaded in an apparatus body is a suitable product. When the suitable product determining section determines that the toner container is not a suitable product, on condition of successive feeding of sheets, the control section allows, after every predetermined number of sheets have been subjected to an image forming operation, a fixing aging operation for stopping the image forming operation and rotating rotating bodies of the fixing section to be performed. When the suitable product determining section determines that the toner container is a suitable product, the control section keeps the fixing aging operation conditional on successive feeding of sheets from being performed.