A development device includes a toner-containing chamber for containing supplied toner having an interior wall, a developer-containing chamber for containing developer including toner and carrier communicating with the toner-containing chamber; and a transport screw to transport the supplied toner from the toner-containing chamber to the developer-containing chamber, disposed in the toner-containing chamber so that there is no gap between the outer edge of the transport screw and the interior wall of the toner-containing chamber in a portion lower than a level of the supplied toner in the toner-containing chamber.