ANTENNA CIRCUIT CONFIGURING BODY FOR IC CARD/TAG, AND IC CARD

Provided are an antenna circuit constituent body for an IC card/tag, which is capable of enhancing a Q value by reducing a permittivity of a resin film of which a base material is made; and an IC card. The antenna circuit constituent body (10) for an IC card/tag comprises: the base material (11) made of the resin film; and circuit pattern layers (131 and 132) each formed on each of both sides of the base material (11) and made of aluminum foil. The circuit pattern layer (131) includes a coiled pattern layer. Parts of the circuit pattern layers (131 and 132), which mutually face each other; and a part of the base material (11), which is interposed between the parts of the circuit pattern layers (131 and 132), constitute a capacitor. The circuit pattern layers (131 and 132) are electrically connected by means of crimping parts (13a and 13b). The base material (11) includes a plurality of void-state-air layers. A relative density of the base material (11) with respect to a density of a resin is less than or equal to 0.9. An average volume of the void-state-air layers is greater than or equal to 2 µm 3 and less than or equal to 90 µm 3 .