To shorten recovery time for the system of a retail shop by loading copied EPL data for backup for the loss of a primary EPL data file.

The system is provided with a list of plural items and information to identify electronic price labels(EPL) relating to the items, and also, the primary EPL data file 32 following information change is supplied to the system. Also, an EPL data file 34 for backup provided with the list of plural items and the information relating to the items are supplied by copying the primary EPL data file 32 periodically. When the loss is caused in the primary EPL data file 32 due to the destruction of a recording medium, etc., the EPL data file 34 for backup is loaded by a computer terminal 24. In this case, when the EPL data file 34 for backup is not provided with single information with respect to the EPL out of the EPLs included in the system 16, the data file 34 is corrected.