A developing device includes a developer carrying member; a first feeding path in which a developer is to be supplied and fed to the developer carrying member at a position in which the first feeding path opposes the developer carrying member; a second feeding path, communicating with the first feeding path, for forming a circulation path with the first feeding path; a discharge opening for permitting discharge of an excessive developer in the developing device; a first supply opening, located downstream of the first feeding path opposing the developer carrying member with respect to a developer feeding direction and located upstream of the discharge opening with respect to the developer feeding direction, for permitting supply of a first developer containing at least toner; and a second supply opening, located upstream of the first feeding path with respect to the developer feeding direction and located downstream of the discharge opening with respect to the developer feeding direction, for permitting supply of a second developer which has a toner ratio lower than that of the first developer or is consisting only of a carrier.