The base station device and the terminal device

While preventing an increase in the overhead of the uplink control channel, the base station apparatus and the terminal apparatus for realizing flexible retransmission control. The base station (100), the control unit (101), set the Bundling unit band group including a first and second downlink unit band, the mapping unit (108), the first transmission data, the first and second along with the mapping to the downlink unit band, the retransmission data, mapped to the third of the downstream unit band except for the downlink unit band of Bundling unit band group. Further, in the terminal (200), Bundling control unit (212), a response signal to the initial transmission data, provided in the uplink unit band associated with the downlink control channel of the downlink unit bands initial transmission data is transmitted send the configuration resources of the uplink control channel, a response signal to retransmission data, transmitting in different response signal for the initial transmission data resources.