Abstract: A data storage device reads data from and/or writes data to a memory medium. The data storage device includes a storage unit for storing a first identifier, an identifier acquisition unit for acquiring a second identifier recorded on a memory medium which is set to the data storage device, and a controller for comparing the first identifier with the second identifier, and then controlling to access to the memory medium for data reading and/or writing according to a relationship between the first identifier and the second identifier. For example, when the first identifier does not match the second identifier, the controller inhibits access to the memory medium for the reading of data. But, when the first and second identifiers match, the controller permits access to the memory medium for the reading and writing of data.