To provide a storage or the like capable of normally carrying out posterior reading and writing operations even when there is a malfunction during changing operation of an address translation table.

A flash memory 11 stores present and past BPTs (Block Pointer Tables) representing correspondence relationships between physical addresses and logical addresses of blocks. In a controller 12, when writing user data, and writing a new present BPT in a vacant block after user data writing, the BPT is updated in a form including each piece of information indicating an order of usage of vacant blocks for storage of the BPTs, a position of one prior BPT, and whether or not a block previously used for storing the BPT is a defective BPT, in the new BPT. In upcoming initialization, correction or the like of the present BPT is carried out on the basis of the information, and when any piece of the information is missing, contents of the present BPT is specified on the basis of the remaining information.