An image forming apparatus includes developing devices, each of which contains a developing agent of a single color therein; a photosensitive member; a latent image forming device that forms a latent image on the photosensitive member, the latent image being developed into a visible image on the photosensitive member, the visible image being made of developing agent images of each color using the developing agent of the single color supplied by each of the developing devices; and an image receiver member that contacts the photosensitive member and receives the developing agent images of each color formed on the photosensitive member sequentially and electrically. A transfer bias for transfer developing agent images from the photosensitive member to the image receiver member is set lower for the first developing agent image that is transferred than a transfer bias for transferring a second developing agent image.