A developing apparatus includes a toner collection apparatus having a waste toner accommodation chamber that temporarily accommodates waste toner removed from a photosensitive medium. A screw to transfer the waste toner is installed in the chamber. A collection path connects the waste toner accommodation chamber to a developing chamber that holds new toner to be supplied to the photosensitive medium. Waste toner is delivered through the collection path to the developing chamber. An agitator that agitates the waste toner to prevent the collection path from being clogged is provided. The agitator includes a pivoting body installed in the collection path. One end of the pivoting body selectively contacts the screw. The other end of the pivoting body is connected to an agitating body that is arranged in a lengthwise direction of the collection path. As the screw rotates, the pivoting body pivots, thereby moving the agitating body so that it agitates waste toner in the collection path.