A first object of the present invention resides in providing a novel installation structure for an RFID tag, which effectively protects the RFID tag from external stress or impact during the storage, transportation and usage, and allows communication with the external.A second object of the present invention resides in that providing a novel installation structure for an RFID tag, which enables communication with the external even if the RFID tag is installed on a conductive member such as a metal member, and the surface thereof is covered with a protective member typically made of a metal which has an excellent strength and durability.A third object of the present invention is to provide a communication method using an RFID tag as being surrounded by a conductive member typically made of a metal.Even if an RFID tag 1a is housed in a container A typically made of a conductive material such as a metal having a large mechanical strength, the RFID tag 1a can communicate with an external read/write terminal 9 as mediated by leakage magnetic flux if only a flux leakage path 12 composed for example of a gap is formed in such container A.