To provide a flexible card system capable of dealing with a plurality of collation methods with one system.

In the case of using a collation method A, a unique data part for retrieval is defined as 'ALL', and information that the method A is used is set in a collator. In the case of using a collation method B, the unique data part for retrieval is defined as 'non-ALL', and information that the method B is used and a separated digit are set ion the collator. When the method A is set, the whole digits of master data are compared and collated with the whole digits of collation data. When the method B is set, the collation data are separated by the set separated digit, unique data for retrieval in the collation data are compared and collated with unique data for retrieval in the master data, and when coinciding master data exist, incidental information in the coinciding master data is compared and collated with incidental information in the collation data.