An image forming apparatus includes an image bearing member (1); charging means (2) for electrically charging the image bearing member (1); a rotatable developer carrying member (440) for carrying a developer to develop an electrostatic image formed on the image bearing member (1) with the developer, the developer carrying member (440) being supplied with a developing bias voltage (S2) comprising an AC voltage; non-rotatable magnetic field generating means (442c), disposed inside the developer carrying member, for magnetically attracting the developer on the developer carrying member (440), wherein the developer carrying member (440) has a surface elastic layer (442a), and the developer carrying member (440) is press-contacted to the image bearing member (1), and the developer is one component magnetic toner, and a maximum value of an absolute value of the developing bias voltage |V| max (V) and a surface potential of the image bearing member charge by the charging means (2) Vd satisfy, |V|max ≤ |Vd|.