A unit for shielding a transponder includes at least a chip and an antenna
structure with application-specific spatial dimensions and which is
secured to an electrically conductive surface. The unit includes a film
having formed thereon or therein a highly permeable material at least in
an area having the spatial dimensions of the antenna structure of the
transponder. The highly permeable material is subdivided into elongate
shielding elements and free spaces arranged between the respective
shielding elements such that when the substrate has been attached to the
transponder, the shielding elements will be oriented parallel to a
magnetic field induced in the antenna structure of the transponder, so as
to suppress eddy currents which are generated by the electrically
conductive surface in the antenna structure, when the transponder is
being introduced in a magnetic field of a respective reading device.