<p>An image forming apparatus (100) includes a photosensitive drum (3); a first sleeve (21) for carrying a developer containing toner and a carrier having a volume resistivity lower than that of the toner and for developing an image on the drum by rubbing the drum with the developer; a second sleeve (31) for carrying the developer received from the first sleeve and for developing the image by rubbing the drum with the developer carried on the second sleeve; a voltage source (40) for applying a developing bias voltage including a DC voltage component and an AC voltage component to the first sleeve and second sleeve; and a driving device (50) for rotating the first sleeve at a peripheral speed higher than the drum and one (60) for rotating the second sleeve at a peripheral speed which is higher than that of the drum and which is lower than that of the first sleeve.</p>
