To prevent the tapping of the data by detecting the tapping action or unauthorized decoding action of data by the disassembly of an IC card.

This IC card is provided with a switch means whose one acting edge is electrically, mechanically, optically or electromagnetically connected with at least one of an upper cover 102 and a bottom over covering an inside structural body 101 of an IC card 100, and whose electric, mechanical, optical or electromagnetic connection relation with the other acting edge is moved to a nonstationary state when one part of the upper cover 102 or the bottom cover is peeled from the inside structural body 101, which outputs a cover open signal. Also, the IC card is provided with a means which eliminates in a batch data not to be made open to the public, or rewrites the data into a specific value at the time of receiving the cover open signal from the switch means.