PURPOSE: To easily perform retrieval and the update of information by providing an information recording medium for the backup of a data base and for the update of data of short term and long term, and a reader for the information recording medium.

CONSTITUTION: The input of the data is performed at a comparatively long term by providing the information recording medium 14 for the backup of the data base and the update of the data of long term, and the reader 13 for the information recording medium 13. Also, the input of the data of comparatively short term is performed by providing the information recording medium 16 for the update of the data of short term in the data base and the reader 15 for the information recording medium 16. Therefore, both input of the data of the cycles of long and short terms can be recorded on a memory device which becomes the data base at the time of performing the retrieval.