an identification tag is attached to or imbedded in each article a plurality of which are located nearby or stacked together . the identification tag wirelessly communicates with a remote controller such as a hand - held terminal to send data or receive command . electric power to operate the identification card is also wirelessly supplied from the remote controller . the electric power is received only by a particular identification card which is communicating with the remote controller , and is turned off when the communication is completed . the electric power is then supplied to the next identification card which communicates with the remote controller . thus , all the identification tags sequentially send data thereof one by one to the remote controller . the remote controller includes an indicator that indicates whether the communication with all the identification tags is completed , so that the remote controller can be positioned at a right place until the end of the communication .