An image forming apparatus includes: an image bearing member; a developer carrying member; an electroconductive regulating member; and a bias applying portion for applying, to the regulating member, a bias of the same polarity as a polarity of the developer on a surface of the developer carrying member at least during a developing operation. The developer remaining on the surface of the image bearing member after transfer of a developer image is transferred is collected by the developer carrying member. At timing when the developer carrying member is driven in a period other than during the developing operation, a potential difference between the regulating member and the developer carrying member is made zero or a voltage which is different from a voltage applied to the developer carrying member toward a side of a polarity opposite the polarity of the developer is applied to the regulating member.