A turbo encoder is provided to be capable of improving its performance in the case that the redundancy is low. A first constituent encoder (1) of an output device of the turbo encoder inputs a data coding sequence (Xk) directly and outputs a redundant data sequence (Zk). A second constituent encoder (2) inputs data coding information (X′k) mixed with the data coding sequence by an interleaver (3), and outputs a redundant data sequence (Z′k). A buffer (4) holds the data coding information (X′k) mixed with the data coding sequence by the interleaver (3). Thus, the data coding sequence (Xk), the redundant data sequences (Zk), (Z′k) and the data coding information (X′k) held by the buffer (4) are output in this order.