An RFID transceiver device is proposed capable of carrier sensing even when the difference in the carrier frequency between two systems is close to "0". The device includes a control and signal processing circuit (10); a local oscillation circuit (11) that generates a local oscillation signal of frequency that is specified by said control and signal processing circuit; and a reception circuit (14) that demodulates the reception signal using the local oscillation signal frequency that is output from said local oscillation circuit (11); wherein the control and signal processing circuit (10) performs control so as to output, to the local oscillation circuit (11), a local oscillation signal of a reference frequency in the case of ordinary communication, and output, to the local oscillation circuit, a local oscillation signal shifted by a prescribed frequency with respect to said reference frequency in the case of carrier sensing, as a local oscillation signal for demodulating the reception signal in the reception circuit (14).