A developing device includes a carrying roller to carry a developer, a storing section to store the developer, a supplying roller to supply the developer to the carrying roller by contacting the developer to the carrying roller, the supplying roller extending substantially parallel to the carrying roller. A conveying unit is configured to convey the developer stored in the storing section to the supplying roller. The conveying unit includes a pump with a stator having a through-hole, and a rotor disposed in the through-hole of the stator and spirally extended such that a cavity to convey the developer is formed. The rotor conveys the developer in the cavity in an axial direction of the rotor. Air is supplied to the developer, conveyed by the pump to scatter and fluidize the developer.