A guide of a broadcasting program with a computer software product, in which a transmission start time, a name of the broadcasting program, a name of the computer software product, a version number of the computer software product and a terminal type required of a terminal are listed, is transmitted from a center station to each terminal. Also, files of the computer software product are transmitted from the center station to each terminal with video-audio data of the broadcasting program at the transmission start time. In each terminal, a particular terminal type of the terminal and a particular version number of the computer software product downloaded in the terminal are managed. In cases where the particular terminal type of the terminal agrees with the terminal type listed in the guide and the particular version number of the computer software product is higher than the version number listed in the guide, the downloading of the computer software product is judged, and the computer software product is downloaded to the terminal at the transmission start time. Accordingly, the computer software product can be downloaded to user's terminal without requiring a special frequency band used only for the computer software product. Also, because the computer software product received in the terminal is updated, the user can always execute the updated computer software product.