PURPOSE: To shorten the time required for saving a data from a semiconductor memory part and restoring the data to the semiconductor memory part, by providing plural nonvolatile storage parts and data transferring circuits so that they correspond to each other, and also, providing a control part for operating simultaneously the data transferring circuits.

CONSTITUTION: Plural pieces of data transfer circuits are provided against a semiconductor memory part 1, and also, in accordance with these circuits, plural pieces of nonvolatile storage parts are provided. Accordingly, a control part 4 can operate simultaneously each data transfer circuit 30W33, and can operate independently the data transfer circuits 30W33, by which a data transfer between the semiconductor memory part 1 and plural nonvolatile storage parts 20W23 can be executed in parallel, and the time for restoration/saving can be shortened remarkably. In such case, the access time of the semiconductor memory part 1 is high speed, and on the other hand, the access time of the nonvolatile storage parts 20W23 is low speed, therefore, even if a related parallel operation is executed, the semiconductor memory part 1 can execute a data transfer without causing the trouble in a flow of a data by a time division control.