In a data management method for supervising a non-volatile memory having a plurality of blocks erasable in a lump, each of the blocks being formed by a plurality of pages, each of the pages including a redundant area, the aggregate management information is used for data management to enable prompt booting. The distributed management information, as the management information for the respective blocks, is stored in the redundant area of each page, and the aggregate management information supervises data stored in each block, in a lump, in association with the distributed management information. It is verified, at the time of booting, whether the aggregate management information is effective. The data is supervised based on the aggregate management information when the aggregate management information is effective and, when the aggregate management information is not effective, the data is supervised based on the distributed management information.