An OFDM communication apparatus that can set an optimum repetition number to data to be transmitted, thereby improving the error rate characteristic and hence the communication quality. In this apparatus, a repetition number deciding part (153) decides, based on quality information outputted from a quality information extracting part (152), a required repetition number. A systematic bit repetition number deciding part (154) decides, based on the repetition number notified of by the repetition number deciding part (153), an optimum repetition number for the systematic bit. A parity bit repetition number deciding part (155) operates similarly. Repetition parts (103-1, 103-2) repeat the bits in accordance with instructions from the systematic bit repetition number deciding part (154) and from the parity bit repetition number deciding part (155).