In an image forming device including a volume supply type developing device, generation of an aggregate of a developer on a back surface of a layer thickness regulating member is suppressed, while occurrence of an image failure caused by the aggregate is suppressed. An image forming device includes: a photosensitive drum; a developing device including a developing roller; a toner container including a toner sensor; and a control portion. According to an increase or decrease of a retention part formed in a first transport path, a toner flows into the developing device from the toner container. The control portion causes the developing roller to reversely rotate at predetermined timing when the toner sensor senses that a residual amount of a toner in the toner container falls below a predetermined threshold value.