According to one embodiment, a non-volatile semiconductor storage device includes a control circuit. When performing a read operation, the control circuit is configured to: apply a first voltage to a selected word line that is connected to a selected memory cell, the first voltage being a voltage between a plurality of threshold voltage distributions; apply a second voltage to a first unselected word line adjacent to the selected word line, the second voltage being not more than the first voltage; apply a third voltage to a second unselected word line adjacent to the first unselected word line, the third voltage being not less than a read pass voltage at which non-volatile memory cells become conductive; and apply the read pass voltage to a third unselected word line, the third unselected word line being an unselected word line other than the first unselected word line and the second unselected word line.