A material 2 is used as the fabric of a shirt, and formed by knitting a blended yarn of polyester and urethane. The material 2 is flattened by a calendering process. A conductive ink is printed on an insulating layer serving as an underlayer to form wiring layers L1 to L10. The conductive ink contains carbon nanotubes. Consequently, wiring layers that ensure a sufficient conductivity can be obtained.