To provide a developing device, an image forming apparatus and a developing method preventing contamination caused by a developer.

The developer including toner and magnetic powder is replenished to a developer carrier on a surface of at least one of the developer carrier, the magnetic powder is recovered together with an excessive developer, by a carrier recovery member provided in a downstream of a developer separation area portion to which a magnetic force of a developer attractive means for attracting the magnetic powder does not reach, and a replenish amount of the developer is detected to regulate the replenish amount of the developer.