To provide a method and a device for backing up a data base for not holding backup data whose acquisition is not required on a secondary storage medium to minimize capacity required by the second storage medium used in a memory data base.

In different areas on a main memory, by the respective units of a record unit, a column unit and the combination of the record unit and the column unit, data guaranteed by a recovery processing from a secondary storage means are stored in a guarantee area and the non-guaranteed data are divided for respective guarantee kinds and stored in a non-guarantee area. Then, at the time of performing back-up to the secondary storage means, only the data guaranteed by the recovery processing are backed up to the secondary storage means.