The present invention is related to a negative voltage generating circuit for reliably providing the semiconductor integrated circuit (IC) with a negative voltage. An electric charge pumping device generates a negative voltage by pumping an electric charge to a predetermined level supplied to one of a first node and a second node. A controlling device provides first and second pumping clock signal being clocked alternately every predetermined interval in response to a level of the negative voltage. A pumping controller controls an amount of electric charge supplied to the first node and the second node in response to the first and second pumping clock signals. Further, a reset controller resets the first node and the second node of the electric charge pumping means as the level of the negative voltage when the first and second pumping clock signals are inactivated.