Disclosed is a cable identifying system for accurately discriminating one cable from another on site over a long period of time, the system enabling a cable layer or a cable user, when laying out an RFID built-in cable, to do without manually writing any information in the RFID tags built in the cable. One cable having RFID tags built therein can be accurately realized. The individual ID's of the RFID tags are read and stored in a storage apparatus. When a part of the cable is cut, the ID's of the RFID tags nearest to the both end of the cable are read out, and the ID-related data of the RFID tags in the cut-out cable are recorded on a desired medium or electronic information medium.