To effectively utilize a transmission band at multiplexed and arranging files on the transmission band and on a time base, to decide the transmission band overlap of the already multiplexed and arranged files by minimum processing operations and to easily decide the adjustment possibility of the transmission start time of the files.

In a band constitution chart A, the multiplex arrangement on the transmission band and on the time base of the respective files at transmission is stored. Also, in file information B, the file information of the respective files distributed within unit time is stored. In array information C, the transmission start time for indicating the transmission start time of the respective files and information for indicating a used band width for the transmission start time are stored. Based on the file information and the file information from the array information, a file distribution processing D executes the processing of successively multiplexing and arranging the respective files on the transmission band and on the time base of the band constitution chart.