A receiver having a retransmission function is provided for alleviating a degradation in the S/N ratio in an FM radio wave for retransmitting an audio signal extracted from a digital broadcasting radio wave even if a receiving situation deteriorates. When the receiving situation is satisfactory, a modulation level is increased during frequency modulation upon retransmission. When the receiving situation deteriorates, the modulation level is reduced. Simultaneously, depending on the varying receiving situation, the processing performed on the audio signal is switched to monophonic or stereophonic.