A developing device includes a carrying roller configured to carry a developer. A storing section is configured to store the developer. A supplying roller is configured 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 between an outer peripheral surface of the rotor and an inner peripheral surface of the through-hole of the stator, the rotor being configured to convey the developer in the cavity in an axial direction of the rotor by eccentrically rotating. An air supplying unit is configured to supply air to the developer conveyed by the pump to scatter and fluidize the developer.