A developing device includes a developing roller, a housing, and a film member. A side opening provided in the housing communicates with a suction device at an end in a rotation axis direction of the developing roller. A downstream cover portion of the housing covers the developing roller from a downstream side in a rotation direction of the image carrying member. Concave portions of the downstream cover portion and a portion of a film member bonded to the downstream cover portion form ducts that communicate from openings facing the image carrying member to the side opening.