To perform communication between an IC tag and a reader more accurately than a conventional case even when a housing is made of metal.

This IC tag possessing body 101 has an IC tag 90 like a flat plate capable of performing radio communication, an electromagnetic shield member 104 like a flat plate for suppressing electromagnetic wave noise, and a resin part 103 for covering the whole of the IC tag 90 and the electromagnetic shield member 104 while they are overlapped. The tag holding body has the IC tag possessing body 101 and a metallic holding body 102 provided with a recessed part. The IC tag possessing body 101 is put in the recessed part so that the electromagnetic shield member 104 is closer to a bottom of the recessed part than the IC tag 90.