The semiconductor memory device of this invention includes a plurality of bit lines for carrying data read out from memory cells and supplying the data to a sense amplifier, the device including: a bias voltage generator for generating a first bias voltage and a second bias voltage which are different from each other; a first precharger for precharging at least one selected bit line to a first precharge voltage obtained based on the first bias voltage generated by the bias voltage generator; and a second precharger for preliminarily precharging each bit line to a second precharge voltage obtained based on the second bias voltage generated by the bias voltage generator.