PURPOSE: To read a bar code where a POS system is not installed by providing an antenna for radiating an output signal, generated by modulating and amplifying read code data, into the air.

CONSTITUTION: The code data which is read by a bar code read part 4 and an ID code setting part 5 is modulated by a signal modulation part 6 in a radio signal, which is radiated as a radio wave into the air from a transmission part 7. A customer reads a bar code provided to an article along through the radio bar code reader device 1. For the purpose, plural bar code reader devices 1 are set to mutually different ID codes and used and articles which corresponding to bar code data sent from the respective bar code readers are passed on payment. Consequently, the customer need not bring an article to be purchased to the installation position of the POS system by himself or herself.