A semiconductor memory device includes a low voltage supplier for supplying a low voltage lower than a ground voltage; a voltage selector for selecting one of the low voltage and the ground voltage; and a word line driving circuit for driving a word line in response to an output of the voltage selector. The voltage selector operates when a self refresh signal is inputted, and supplies the low voltage as a voltage of logic low level used in the word line driving circuit in a self refresh mode and supplies the ground voltage as a voltage of logic low level used in the word line driving circuit in modes other than the self refresh mode.