An image forming apparatus includes a latent image carrier, a container that contains a developer including a toner, developer transport members disposed so that peripheral surfaces thereof face the latent image carrier, a power supply that supplies voltages to the developer transport members, a detector that detects a toner concentration of the developer, and a controller. The controller performs control so that the power supply supplies to the developer transport members, when the toner concentration detected by the detector is higher than a predetermined upper limit, voltages having waveforms that generating a potential difference therebetween that causes the toner concentration of the developer distributed to a most downstream developer transport member to decrease and the toner concentration of the developer distributed to at least one of the developer transport members that is disposed upstream of the most downstream developer transport member to increase.