The present invention provides a semiconductor memory device comprising: a
first conductivity type semiconductor substrate; and a plurality of
memory cells constituted of an island-like semiconductor layer which is
formed on the semiconductor substrate, and a charge storage layer and a
control gate which are formed entirely or partially around a sidewall of
the island-like semiconductor layer, wherein the plurality of memory
cells are disposed in series, the island-like semiconductor layer which
constitutes the memory cells has cross-sectional areas varying in stages
in a horizontal direction of the semiconductor substrate, and an
insulating film capable of passing charges is provided at least in a part
of a plane of the island-like semiconductor layer horizontal to the
semiconductor substrate.