By limiting a backup object to a particular one, it is possible to reduce the system load and perform effective automatic backup. By using a hard disc device or the like, a first storage unit (40) and a second storage unit (70) are prepared. When the system is started, a spreading and storing unit (30) formed by a device driver spreads an OS program and an application program A on a memory (20). The programs are executed by a program execution unit (10). An application to be backed up is registered in advance in an application registration unit (50). A backup management unit (60) monitors operation of the spreading and storing unit (30). Only when particular data in the memory (20) is stored in the first storage unit (40) according to the storing instruction by the registered application, the backup management unit (60) performs a backup process, i.e., stores the particular data also in the second storage unit (70).