A semiconductor memory device includes a plurality of word lines, first and second bit lines, a plurality of memory cells which are connected to the first and second bit lines, a differential amplifier which is connected to one end of the first bit line and one end of the second bit line, a reference-current generating circuit which is connected to the other end of the second bit line and which generates a reference-current smaller than the cell current of the memory cells, and a dummy word line which is connected to the reference-current generating circuit, to activate the reference-current generating circuit in order to read data.