An image forming apparatus includes a body, an image carrier provided in the body and configured to form an image thereon, a first gear to transmit a rotation driving force to the image carrier, a first rotary shaft to which the image carrier and the first gear are attached, a second gear to mesh with the first gear and transmit the rotation driving force to the first gear, a second rotary shaft to which the second gear is attached, a drive source configured to drive to rotate the image carrier via the first gear and the second gear, a first holder to hold the first rotary shaft of the first gear, and a second holder to hold the second rotary shaft of the second gear, and a relative position between the first holder and the second holder therein is adjustable.