1. A control method of a non-volatile memory apparatus comprising: a controlling step of controlling data writing and data readout of said non-volatile memory, by using an erased table indicating whether a physical block which is an erasing unit of data of the non-volatile memory is erased or not, and a logical address/physical address conversion table which converts a logical address to a physical address; a first flag writing step of writing a fixed value, which indicates that data is written, on a first flag existing in a redundancy area on a first page of a physical block and indicating whether data is written onto the first page or not, wherein the first page is within a plurality of pages which are included in said physical block, have data areas and said redundancy areas, and each of which is a minimum data writing unit; and a data writing step of writing data onto the physical block.