PURPOSE: To reduce the number of retrievals by dividing an address space into a primary group and a secondary group, providing a linking means for linking entries belonging to each group, and executing a decision of hit/miss of a cache by the linking means at the time of data access.

CONSTITUTION: In the hit/miss decision processing at the time of data access, first of all, from a source address 43, a first group address 46 and a primary member address 47 are generated by using a generating function 44. From the address 47, a secondary group address 48 and a secondary member address 49 are generated. Subsequently, an entry 30 indicated with the primary group address 46 is referred to, and the secondary group address 48 and the secondary group address in the entry 30 are compared. When they coincide with each other, furthermore, they are compared with the secondary member address, and when they coincide with each other, it is decided to be a hit. Unless they coincide with each other, the comparison with the secondary member address is continued by referring to the entry indicated with a link pointer.