A developing device includes a housing, a developer holding device, and a directing device. The housing includes a container portion containing developer and has a developing opening. The developing device has a through portion disposed at a portion of the housing including a downstream edge portion at a downstream portion of the developing opening in a direction in which the developer holding device is rotated. The through portion has an inlet, an outlet, and a passage that connects the inlet and the outlet to each other so as to allow part of an airflow generated by rotation of the developer holding device to be introduced thereinto and flow therethrough. The directing device extends from a portion of the housing opposite to the developing opening with the inlet of the through portion interposed therebetween toward the developer holding device so as to direct the part of the airflow toward the inlet.