Abstract: A memory system includes a non-volatile memory which is configured in units of erasable blocks each having a first size and units of pages each having a second size within each block, a page size identification information storage unit configured to store a third size that is smaller than the second size, and a control unit configured to convert a first address designated in a command received by the memory system into a second address. The first address specifies a page number of pages having the third size and the second address specifies a page number of pages having the second size.