An OFDM communication apparatus and an OFDM communication method that realize both an improvement in efficiency of transmitting information signals and an improvement in error rate characteristic of demodulated signals in OFDM systems using multicast. The OFDM communication apparatus comprises receiver means for receiving an OFDM signal transmitted to a plurality of OFDM communication apparatuses; detector means for detecting errors, if included in the received OFDM signal; generator means for superimposing, if the received OFDM signal includes any errors, a retransmission request signal on a predetermined subcarrier to thereby generate a retransmission request OFDM signal; and transmitter means for transmitting the generated retransmission request OFDM signal in a timing predetermined in common to all the foregoing plurality of OFDM communication apparatuses. |