A non-volatile semiconductor storage device includes a plurality of memory strings each having a plurality of electrically rewritable memory cells connected in series. Each of the memory strings comprising: a first semiconductor layer including a columnar portion extending in a vertical direction with respect to a substrate; a plurality of first conductive layers formed to surround side surfaces of the columnar portions via insulation layers, and formed at a certain pitch in the vertical direction, the first conductive layers functioning as floating gates of the memory cells; and a plurality of second conductive layers formed to surround the first conductive layers via insulation layers, and functioning as control electrodes of the memory cells. Each of the first conductive layers has a length in the vertical direction that is shorter than a length in the vertical direction of each of the second conductive layers.