A developing device for image forming equipment capable of agitating and mixing a fresh toner and a developer sufficiently is disclosed. The device eliminates a change in image density among individual copies, irregularity in density corresponding to the spiral pitch of, for example, a toner transport screw, and irregularity in density in the front-and-rear direction (axial direction of a developing sleeve) ascribable to defective agitation. To replace or clean a desire part or parts built in a developing device, the device is divided into two such that the desired parts are freely accessible. This facilitates the cleaning and replacement of such parts.