A non-volatile semiconductor storage device includes: a memory cell array including memory strings, each of the memory strings having: a first end; a second end; and a plurality of memory cells connected in series between the first end and the second end, the memory cells being categorized into memory cell groups; a first end that is one end of the memory string; and a second end that is the other end of the memory string; first selection transistors connected to the respective first ends of the memory strings; a plurality of second selection transistors connected to the respective second ends of the memory strings; bit lines connected to the respective second selection transistors; word lines connected to the memory cells; and a control circuit configured to apply different control voltages to the respective word lines.