To search the location of IC card, coin or tag from a distant place by providing the inside of tag or seal-shaped object with a light emitting element and/or sounding element to operate corresponding to a received external signal.

A tag 3 is attached through a ring 2 to a key 1 of car or house. A light emitting element 4 such as LED or lamp and/or sounding element 5 such as buzzer and a battery 6 are attached to the tag 3. The signal received from the outside by an antenna provided in the tag 3 is appropriately selected, amplified by a reception circuit and decoded by a demodulation circuit. This decoded signal is a code signal for identifying the owner of the key 1, for example, and when the signal is collated with stored owner information and the both are coincident, the light emitting element and/or sounding element 5 is driven. As a result, since the tag 3 generates light or sound, the lost key 1 can be discovered.