A developing device has a developer container, first and second stirring members, a developer carrier, a developer supply port, and a developer discharge port. The developer container has transport chambers including the first and second transport chambers, and communication portions through which the first and second transport chambers mutually communicate. The first stirring member has a rotary shaft and a first helical blade. The second stirring member has a rotary shaft and a second helical blade. The second stirring member has a regulating portion for regulating movement of developer toward the developer discharge port. The regulating portion has two or more turns of regulating blades spiraling in the opposite phase to the second helical blade. The gap between the regulating blades and the inner wall surface of the developer container is gradually small from upstream to downstream with respect to the developer transport direction in the second transport chamber.