A physical space management table is disposed outside the microprocessor in order to hold attribute data of the regions of the physical space held as a set of a plurality of regions in a manner corresponding to the regions of the physical space. The microprocessor is provided with a physical space management unit which fetches the attribute data from the physical space management table and manages them. The physical space management unit includes a physical space management table search control circuit, and a physical data buffer which primarily holds the attribute data obtained by the physical space management table search control circuit and the physical address in a manner corresponded to each other.