The present invention is directed to a semiconductor integrated circuit device having reduced leakage and the method of operating a semiconductor integrated circuit device with reduced leakage. The invention comprises an integrated circuit, including a passing transistor and a bias-application device coupled to the substrate of the passing transistor. The present invention has the passing transistor coupled to a storage cell. The bias-application device applies a first bias voltage of a positive value when the passing transistor is inactivated and applies a second bias voltage when the passing transistor is activated, wherein the second bias voltage is equal to or smaller than the first bias voltage. Further in accordance with the invention, there is provided a method of reducing the leakage of a passing transistor of N-type. The passing transistor is coupled with a storage cell. The method includes applying a first bias voltage of a positive value when the passing transistor is inactivated, and applying a second bias voltage when the passing transistor is activated, wherein the second bias voltage is equal to or smaller than the first bias voltage.