The present invention provides IC tags which can not easily be broken nor give any hazard to human health, which enables minimization of aborted tags, shortening of time required for deletion of recorded data, minimization of sanitary and environmental problems, and reuse of tags to substantially reduce the cost for a management system. A metal antenna and an IC chip are coupled to and integrated with each other to form an IC chip-mounted body. Then, the IC chip-mounted body is covered with ceramic cladding members to form an IC tag. The metal antenna is formed by winding a metal wire into a coil form. A ceramic filler is used for coupling the ceramic cladding members to each other and also tightly securing the IC chip-mounted body to the ceramic cladding members.