A developer replenishing apparatus includes: a developer storing container for storing a developer therein; a first driving source for rotating the developer storing container to supply the developer; a developer reservoir section for receiving the developer supplied from the developer storing container; a conveying screw for replenishing the developer in the developer reservoir section onto a developing device; a second driving source for driving the conveying screw; and a stirring member for stirring the developer in the developer reservoir section, the stirring member having a first and second one-way clutches provided on a driving shaft thereof. The stirring member is driven by the first driving source through the first one-way clutch, and driven by the second driving source through the second one-way clutch.