This invention relates to a terminal apparatus that can possibly reduce situations in which upstream channel data are punctured by a plurality of response signals. When having received at least one piece of downstream allocation control information corresponding to a second downstream unit band, which is other than a first downstream unit band, of a plurality of unit bands, a control unit (208) maps a plurality of response signals, which are corresponding to the respective ones of the plurality of downstream unit bands established, to a first resource corresponding to the plurality of downstream unit bands established. When having received only the downstream allocation control information corresponding to the first downstream unit band of the plurality of unit bands established, the control unit (208) maps the response signal, which is corresponding to the first downstream unit band, to a second resource corresponding to the first downstream unit band.