To speedily and stably transmit/receive data by facilitating positioning when an RFID reader/writer antenna accesses an RFID card attached inside the terminal box of a microcomputer meter by applying a device to a wireless meter-reading system based on the utilization of the RFID card.

A position indication seal or pointer 15 as shown in the figure is previously located at the top end of an RFID reader/writer antenna positioning device 21. A cohesive agent or adhesive agent is applied to the pointer 15. A positioning worker makes the RFID reader/writer antenna positioning device 21 close to a terminal box 11 attached with an RFID card 13 and while watching swinging of the pointer of an indicator 21a, the pointer 15 is stuck on the terminal box 11 at a position, where the radio wave of RFID becomes a maximum level. With the stuck pointer 15, the meter-reading person of the microcomputer meter can transmit/receive data with the RFID reader- writer antenna at the optimal position at all times.