A developing device for forming an image by developing an electrostatic latent image formed on an image carrier with a developer, includes: a developing container that accommodates the developer; a developing roller that faces the image carrier, is disposed adjacent to the developing container, and conveys the developer accommodated in the developing container to the image carrier, and a developer discharging part that is provided in the developing container and discharges a part of the developer, wherein a discharge amount of the developer discharged by the developer discharging part is controlled on the basis of a charge amount of a toner included in the developer.