A semiconductor storage device include a semiconductor substrate, an insulating layer provided on the semiconductor substrate and having an opening, a semiconductor layer provided on the insulating layer, the semiconductor layer having a recess at a center of a surface thereof above the opening, a memory cell unit provided on the semiconductor layer and including a plurality of memory cells, current paths of the memory cells being connected in series, a selecting transistor adjacent to the memory cell unit and arranged on a region of the semiconductor layer including the recess, the selecting transistor including a gate insulating film provided on the region of the semiconductor layer including the recess and a gate electrode provided on the gate insulating film.