Disclosed are a transmission device and a transmission method with which it is possible to prevent delays in data transmission and to minimize the increase in the number of bits necessary for the notification of a CC to be used, in cases where a CC to be used is added during communication employing carrier aggregation. When a component carrier is to be added to a component carrier set, a setting section (101) provided in a base station (100): modifies a CIF table that defines the correspondence between code points, which are used as labels for the respective component carriers contained in the component carrier set, and the identification information of the respective component carriers; and assigns a vacant code point to the component carrier to be added, while keeping the correspondence between the code points and the component carrier identification information defined in the CIF table before modification.