An image forming apparatus, includes an image bearing member having an endless belt shape, on which a toner image is formed, and the image bearing member, a drive roller, which rotates the image bearing member laid around the drive roller, a drive gear, which is connected to the drive roller, and a drive transmitting gear, which is engaged with the drive gear, and transmits a driving force to the drive gear to rotate the image bearing member. The drive transmitting gear is arranged so that a direction of a drive reaction force of the drive transmitting gear with respect to the drive gear substantially coincides with an ingress direction of the image bearing member toward the drive roller.