A relay station comprises an emergency information detection unit for detecting an emergency information broadcasting flag in the digital broadcasting TMCC signal transmitted from the center station; a replacement data creation unit for issuing an instruction for creating replacement contents and replacing the data when emergency information is multiplexed in the TS; and a time synchronization unit for executing time synchronization between the TS created by the data replacement and the TS before the data replacement. On a receiving terminal, the replaced data broadcasting contents can be received while prefectural broadcasting video and audio contents are continuously received.