An image forming apparatus of the present invention includes a plurality of image carriers arranged side by side and a charging device, exposing device and developing device arranged around each image carrier. An image transferring unit includes an image transfer belt and a plurality of bias applying members for applying image transfer biases to image transfer nips formed between the bias applying members and the image carriers, which face each other with the intermediary of the image transfer belt. Each image transferring member has an axis positioned downstream, in the direction of movement of the image transfer belt, of a virtual vertical line extending from the axis of the associated image carrier downward. At least two of the bias applying members are provided with respective belt holding members at the downstream side in the direction of movement of the image transfer belt.