A non-volatile memory device includes a first sector including a first sector selection transistor and a first plurality of pages connected to the first sector selection transistor, and a second sector including a second sector selection transistor and a second plurality of pages connected to the second sector selection transistor. Each of the first and second plurality of pages includes a memory transistor and a selection transistor, and a number of pages in the first plurality of pages is greater than a number of pages in the second plurality of pages.