A cache memory includes a CAM with an associativity of n (where n is a natural number) and an SRAM, and storing or reading out corresponding data when a tag address is specified by a CPU connected to the cache memory, the tag address constituted by a first sub-tag address and a second sub-tag address. The cache memory classifies the data, according to the time at which a read request has been made, into at least a first generation which corresponds to a read request made at a recent time and a second generation which corresponds to a read request made at a time which is different from the recent time. The first sub-tag address is managed by the CAM. The second sub-tag address is managed by the SRAM. The cache memory allows a plurality of second sub-tag addresses to be associated with a same first sub-tag address.