Developing device with airflow

A developing device includes a toner holding member that rotates while holding a toner on an outer peripheral surface of the toner holding member and develops an electrostatic latent image formed on an image carrier, a control member that controls a thickness of a layer of the toner formed on the outer peripheral surface of the toner holding member, a suppression member that has an end pressed against the image carrier and that suppresses leakage of the toner, a collecting member that is provided above the control member and that does not allow the toner flowing in a direction from the control member toward the collecting member to pass through the collecting member while allowing a gas to pass through the collecting member, and a containing chamber that contains the toner falling from the collecting member.