A non-volatile semiconductor memory device according to an embodiment includes: a data write portion configured to repeat a write loop until data write is complete, the write loop including a program operation of applying a selected word-line with a program voltage necessary for program and a verify operation of applying the selected word-line with a verify voltage necessary for verify, the program voltage being changed for each write loop by a predetermined step width, the data write being performed in units of a page including a plurality of memory cells selected by the selected word-line; and an endurance determination portion configured to determine the endurance of the memory cells of the page, the data write portion supplies the selected word-line with a program voltage of a step width depending on the endurance.