To improve security by preventing the tampering or the like of data in an IC tag.

The IC tag is constituted of three parts, i.e. separable parts A1 and A2 and a non-separation part B (a tag body). The parts A1, A2 and A3 are provided with an IC1, an IC2 and an IC3 and antennas 1, 2 and 3 being interfaces with external apparatuses, respectively. The IC1 and the IC2 are connected by a signal line L1 for signal transmission, whereas the IC2 and the IC3 are connected by a signal line L2 for signal transmission. The signal line L1 is wired so as to be simultaneously disconnected when the part A1 is separated from the tag body, and the signal line L2 also is wired with a layout so as to be disconnected when the part A2 is separated from the tag body.