An antenna conductor and a reinforcing layer are provided on an upper surface and a lower surface, respectively, of a flexible base film. An RFIC element is mounted on the upper surface of the base film. Two I/O terminals provided on the RFIC element are each connected to meander patterns of the antenna conductor. In a plan view, the reinforcing layer has a circular contour, and the RFIC element is surrounded by the contour of the reinforcing layer. The two I/O terminals provided on the RFIC element are exposed on the upper surface of the base film. Breakage of the connected portion between the RFIC element and the antenna conductor is prevented, and any breakage that has occurred is easily identified.