A developing apparatus includes a rotatable developer carrying member for carrying one component developer to a developing zone for developing an electrostatic latent image for an image bearing member; a regulating member for regulating a thickness of a layer of the developer to be carried by the developer carrying member to the developing zone; a rotatable developer, in contact with the developer carrying member, for supplying the developer; a developer guiding portion for guiding reverse movement of the developer blocked by the regulating member; wherein 0.02.ltoreq.d/Vs.ltoreq.0.1 is satisfied, where d is a minimum distance between the developer guiding portion and the developer feeding member (mm), and Vs is a peripheral speed of the developer feeding member (mm)/sec.