A memory management method for managing a non-volatile memory into which writing is performed in units of blocks includes the steps of assigning a plurality of blocks of the non-volatile memory to a management area formed of at least one block for storing management information, to a code area formed of a plurality of blocks into which program code is written, to a substitution area formed of a plurality of blocks for substituting for a defective block, and to an interference area formed of at least one block; storing at least correspondence information between the blocks of the substitution area and a defective block of a substitution target as management information within the management area; and using the block of the substitution area in place of the defective block on the basis of the correspondence information when the defective block is to be used.