An image forming apparatus includes: a recording medium supplying device that supplies a recording medium; an image carrier arranged beneath the recording medium supplying device in a gravitation direction; a carrying passage that transports the recording medium supplied from the recording medium supplying device, and arranged between the recording medium supplying device and the image carrier and having a horizontal carrying portion which extends approximately in a horizontal direction and serves to carry the recording medium; and a transferring unit that transfers, at the horizontal carrying portion of the carrying passage, a toner carried by the image carrier onto a lower surface in the gravitation direction of the recording medium supplied from the recording medium supplying device.