To provide a rubber belt with a flat surface on the back with no level difference between a region where a mark is transferred and a region where it is not transferred, having improved transmitting performance, and to provide its manufacturing method.

The belt is formed of a rubber as a base material with a core 2 embedded along the longitudinal direction. A rubber layer is formed of at least a rubber only on the back of the belt where the mark 15 with no level difference is provided flush therewith.