To stick to the surface of a noncontact IC card a seal element on which ID information including the photograph and the name of the user and other visual information are printed, thereby providing the noncontact IC card with an authentication function to use it as both a security key for electronically or mechanically determining whether or not access to a controlled area is permitted and a visual identification tag for identifying its owner.

The seal element 1 is stuck to at least a third or more of the area of the surface of the noncontact IC card 3. The seal element 1 comprises a label layer 12 and an adhesive layer 12 stacked or laid one on top of the other on one sticking side (reverse side) of a translucent resin film 11, with visible information printed as a reverse image on the label layer 12, and the adhesive layer 12 capable of being removably stuck to the surface of the card 3. The layers are fixed to and integrated with the surface of the card 3. The label layer 12 is formed by creating using a computer the content (visual information) of an article including an image of an employee ID card, a membership card, an admission card, a pass or other ID card, a permit card or a certificate, and printing it for output. The adhesive layer 13 is made of a double-sided adhesive sheet 131.