A memory device with a nonvolatile memory and RAM for accessing the nonvolatile memory is generally provided with a table to convert a logical address to a physical address, however, in the invention, the table is divided to a first table on RAM and a second table on the nonvolatile memory. The first table converts specific bits of the logical address to a first physical address indicating a location of the second table. The second table converts the other bits of the logical address to a physical address of a representative page of pages contained in a storage area corresponding to the logical address. A unit operable to access data (a writing unit operable to, a reading unit operable to, and an erasing unit operable to) reaches a target physical address based on the logical address. Such configuration can reduce the capacity of each conversion table.