A multicarrier communication apparatus that is capable of suppressing interference of feedback information with other channels and alleviating a reduction in an uplink capacity. In PL signal reception section of this apparatus, PL signal extraction section extracts pilot signals and reception quality measuring section measures reception quality such as an SIR. Here, since pilot signals are included in respective subcarriers, reception quality measuring section measures reception quality of subcarriers. FBSC determining section determines a feedback information subcarrier based on the reception quality of subcarriers. More specifically, FBSC determining section determines a subcarrier having the highest reception quality as a feedback information subcarrier. FBSC determining section outputs information about the feedback information subcarrier (FBSC information) to control CH transmission section and FB information reception section.