Disclosed is a radio communication device capable of improving the usage efficiency of resources in multi-stage relay to reduce the amount of delay of a relay signal and improving the reception quality of signals by a relay station or a base station. A transmission determining unit 16 determines whether to transmit the relay signal and whether to transmit ACK/NACK on the basis of whether there is an error in the relay signal, and on the basis of ACK/NACK received from a one-hop-downstream radio communication device. An MCS determining unit 17 provided in the transmission determining unit 16 determines an MCS for the relay signal. A transmission instruction generated by the transmission determining unit 16 is output to a buffer 11 and an ACK/NACK generating unit 19. The determined MCS is output to an error correction coding unit 12 and a modulation unit 13. The ACK/NACK generating unit 19 generates ACK when there is no error in the relay signal, and generates NACK when there is an error in the relay signal.