A non-volatile semiconductor storage device has a plurality of memory strings with a plurality of electrically rewritable memory cells connected in series. Each of the memory strings includes: a first columnar semiconductor layer extending in a direction perpendicular to a substrate and having a first hollow extending downward from its upper end; a first insulation layer formed in contact with the outer wall of the first columnar semiconductor layer; a second insulation layer formed on the inner wall of the first columnar semiconductor layer so as to leave the first hollow; and a plurality of first conductive layers formed to sandwich the first insulation layer with the first columnar semiconductor layer and functioning as control electrodes of the memory cells.