An object of the present invention is to provide an analog-digital conversion service transaction system and a method thereof that can convert the analog information media into the digital information media without taking much trouble or costing much money. A distributor requested to convert analog information media into digital information media accesses to a converting center terminal by using a distributor terminal via a network, and transmits request order information to the converting center terminal. The conversion terminal, when receiving the request order information, calculates a time and date whereat the digital information media become available for a delivery, and transmits them to the distributor terminal. The client either receives the digital information media by visiting the distributor after the time and date whereat the transfer can be done, or receives the content of digital in formation media by an e-mail transmitted by the client terminal.