Abstract: A semiconductor memory device comprises memory cells that store data by accumulating or discharging an electric charge; memory cell arrays that have a plurality of the memory cells disposed in a matrix; a plurality of word lines that are connected to the memory cells arrayed in rows of the memory cell arrays; a plurality of bit lines that are connected to the memory cells arrayed in columns of the memory cell arrays; a plurality of dummy cells that are arrayed in a row direction of the memory cell arrays and are connected to the bit lines; sense amplifiers that detect data within the memory cells by using an average value of electric characteristics of the dummy cells that plurality of switching elements that electrically connect four or more of the bit lines in order to generate the reference signal.