A digital broadcast system includes a digital broadcasting device which transmits service data together with a broadcast program, wherein the service data includes an application which allows a digital broadcasting receiver to perform a particular operation and information associated with the operating mode of the application. The digital broadcast system also includes a digital broadcasting receiver which receives the service data and executes the application when the operating mode of the application is an initial operating mode, and otherwise, waits until there is a service request by a viewer, and then executes the application. The digital broadcast system for broadcasting additional service data together with broadcast programs can arbitrarily select the point of time at which an application provided to a digital broadcast receiver is executed, during the manufacture of contents, so that various types of interactive services can be provided.