A substrate of a touch panel has a body, a dielectric layer and multiple wires. The dielectric layer is formed on the bottom surface of the body and has multiple sensing areas and a wiring area. The wiring area is formed around the sensing areas and has multiple rough surfaces formed on the wiring area and being identical to the sensing areas in number. The wires are identical to the sensing areas in number. Each wire is formed on one of the rough surfaces of the wiring area and is electrically connected with one of the sensing areas. The formation of the wires on the respective rough surfaces can enhance adhesion of the wires so that the wires do not easily come off or get fractured.