Inserting adverts/commercials in video on demand

In a video server used for a video-on-demand system, a special video program, such as an advert or commercial video program, is transmitted from a special video storage unit 41 of the video server to each subscriber terminal within a nontransmission time which takes place during a searching time for a video program requested by the subscriber and/or during an execution time of a specific reproduction control command, such as a "FAST-FORWARD" command, a "FAST-REWIND" command. The transmission of the special video program is not stopped even when a reproduction control command is given from the subscriber to the special video storage unit by judging the reproduction control command to be invalid while a reproduction control command related to video programs different from the special video program is executed by judging the commands to be valid.