To provide a transmission belt and a method of manufacturing the transmission belt excelling in machinability, adhesive property, wear resistance and durability.
A toothed belt 1 has a plurality of tooth parts 2 along the longitudinal direction of the belt, and a belt body composed of a back part 4 with core wires 3 embedded. Tooth cloth 5 is stuck to the surface of the tooth parts 2 if necessary. The tooth part 2 is composed of a crosslinked substance of a rubber composition prepared by mixing 1-50 pts.mass of unsaturated calboxylate ester containing active hydrogen into 100 pts.mass of a rubber component containing hydrogenated nitrile rubber. Specific examples of unsaturated calboxylate ester can be methacrylate ester and/or acrylic acid ester containing a hydroxyl group and/or a carboxyl group.