A dynamic type semiconductor memory device includes a sense amplifier connected with a bit line pair to amplify and sense a voltage difference on the bit line pair; a precharge circuit configured to precharge the bit line pair to a power supply voltage on a lower side in response to a first control signal; a memory cell capacitance having one end which is connected with the bit line pair through a first switch circuit which is controlled in response to a signal on a word line; and a reference cell capacitance having one end which is connected with the bit line pair through a second switch circuit which is controlled in response to a signal on a reference word line. The other end of the memory cell capacitance and the other end of the reference cell capacitance are electrically separated.