Provided are a digital broadcasting transmitting/receiving apparatus and method. By converting content of a main-program to a stream, converting content of a sub-program forming a single digital broadcasting service through synchronization with the main-program by being subordinated to the main-program to a stream, generating program configuration information containing stream conversion information of the main-program and stream conversion information of the sub-program, multiplexing the converted main-program stream and the generated program configuration information and real-time transmitting the multiplexed signal, and transmitting the converted sub-program stream in non-real-time, various and new premium services with compatibility with existing digital broadcasting services can be provided to users.