The developing device of the present disclosure comprises a developing container, toner carrier, developer carrier, regulating member, and air outflow channel. The developing container accommodates a two-component developer. The toner carrier supplies toner to an image carrier. The developer carrier rotates so that a surface facing the toner carrier moves in the opposite direction of the toner carrier, and a toner layer is formed on the toner carrier. The regulating member regulates the amount of developer carried on the developer carrier. The air outflow channel communicates an airflow outlet formed in the top end of the developing container facing the toner carrier with the interior of a duct placed above the developing container, and the air outflow channel is inclined downstream in the rotational direction of the toner carrier relative to a straight line passing through the rotational axis center of the toner carrier and the airflow outlet.