A radio data communication apparatus includes a circuit unit and at least one antenna unit. The circuit unit performs data read and write operations relative to an IC tag. Each antenna unit has an antenna and conducts a predetermined signal modulation to a first signal to be transmitted through the antenna by radio to a specific IC tag in the data write operation. Also, each antenna unit conducts a predetermined signal demodulation to a second signal received through the antenna from the specific IC tag in accordance with the data read operation. The antenna unit is arranged at a position separated from the circuit unit.