Abstract: “The radio-frequency identification device includes embedded in an envelope a substrate on one face of which an antenna is produced and a chip connected to the antenna is positioned, a potting locally covering the substrate face level with the chip, an intermediate layer made of a magnetic superconductor material placed against the substrate on the antenna side, the intermediate layer having dimensions greater than those of the antenna so as to be able to cover the antenna and having a cavity arranged so that the potting and the chip can be approximately completely housed therein.