A developing device includes an image carrier, a developer carrier, a biasing unit disposed upstream of a developing area, and a controller configured to control the biasing unit, and a cleaning member disposed downstream of the developing area to remove the liquid developing agent remaining on the developer carrier. A latent image held on the image carrier may be developed with the liquid developing agent, including charged toner and a carrier liquid, at the developing area where the developer carrier faces the image carrier. The controller causes the biasing unit to apply a first bias voltage to the surface of the liquid developing agent held on the developer carrier during developing, or a second bias voltage thereto during cleaning.