A data storage system, which includes a plurality of pages, each of which includes a plurality of first memory cells, from which at least binary data can be read-out a plurality of times without destruction; a circuit which receives data-output of at least one first page, detects an error in at least one bit of data, and outputs information of the error position; another circuit which determines whether data of an error bit is "1" or "0". When the determination is "1" or "0", the first memory cell of the first page is erased, and error-corrected data is written.