To provide a sprocket 40 corresponding to a hinge driving and a center driving.
This sprocket drives a modular belt 70 comprising a plurality of belt modules having link ends 72 and 75 from which respective belt modules 71 project in the opposite directions in a belt progressing direction and a rib 37 extending in the crossing direction to the belt progressing direction between the link ends. Each of a plurality of teeth 58 and 61 positioned on the outer periphery has first surfaces 64 for driving the center positioned on a first side surface, and second surfaces 67 for driving the link ends positioned on a second side surface opposite to the first side surface. One of the first surfaces for driving the center of the first tooth engages with one of ribs of the first belt module, and one of the second surfaces for driving the link end of the second tooth engages with one of link ends of the first belt module.