An image forming apparatus, including an image forming unit; a resin-made frame to support the image forming unit; a drive source arranged on a one-end side of a transmission path to generate driving force; a gear arranged on the other-end side of the transmission path to be rotated, while one of axial ends of a shaft of the gear is supported by the frame; a metal-made first supporting member fixed to the frame to support the other of axial ends of the shaft of the gear thereon; a metal-made second supporting member fixed to the frame to support the drive source thereon and; an endless belt; a first pulley supported by the second supporting member to transmit the driving force to the endless belt, the first pulley being; and a second pulley having the endless belt strained there-around and supported by the first supporting member, is provided.