DEVELOPING DEVICE

PURPOSE:To provide a developing device capable of suppressing the splash of a toner with simple structure. CONSTITUTION:There is provided a seal member 13 which is a flexible member disposed in a position opposed to both axial ends of a developing sleeve 12 in a developing housing 10A. The extended direction of this seal member 13 along the rotating direction of the developing sleeve 12 is set, and one end part, corresponding to the rotating direction upstream side, in its extended direction is fixed to the developing housing 10A. The range from this one end part to the other extended-direction end part corresponding to the rotating direction downstream side is curved along the peripheral surface of the developing sleeve 12, and the other end part is pressed flexibly to the inner peripheral surface of the developing housing 10A by the resiliency of its own flexibility generated at the curved time, thus locking the seal member 13. This seal member 13 is partially brought into contact with the peripheral surface in both axial end parts of the developing sleeve 12.