The present invention provides a method for transmitting broadcast signal. The method for transmitting a broadcast signal according to the present invention comprises the steps of: demultiplexing at least one input stream into a plurality of DPs (Data Pipes) wherein the step of demultiplexing includes the steps of dividing the input stream into a plurality of DPs in which data of the plurality of DPs include one or more consecutive input packets, segmenting the data of the plurality of DPs into data units each having the same length as that of a payload of a BB frame, cyclic-shifting the input packets of the divided data, allocating the cyclic-shifted input packets to the payload of the BB frame, and inserting a header before the payload of the BB frame; and processing and transmitting the data of the plurality of DPs per DP.