Abstract:
A contactless information medium includes: a body forming an outer shape of the contactless information medium; an IC chip housed in the body; a coil antenna which is formed of a string of conductive wire, both ends of the conductive wire being connected to the IC chip, and which includes a main arrangement pattern provided along a closed curve and a plurality of sub-arrangement patterns, each of which has a smaller diameter than the main arrangement pattern; and a plurality of bobbins provided in the body and arranged along the closed curve, the string of conductive wire being wound around the plurality of bobbins along the closed curve to form the main arrangement pattern, the string of conductive wire being wound around each of the bobbins to form the sub-arrangement patterns.