To provide a selling managing system, an information processing method and an information recording medium, by which the labor of a user for handwriting entries to a ledger is reduced, the burden on the user for separately managing containers and selling is reduced and the cost can be reduced.

In the selling managing system for managing the selling information on the gas containers, this system is provided with a sales voucher input picture display processing means for displaying a sales voucher input picture for inputting sales information for every commodity and a forwarded container symbol number input screen display processing means for displaying a forwarded container symbol number input screen for inputting the symbol number information of the container related to the inputted commodity on the basis of operation input on the sales voucher input screen.