A high voltage generating circuit is disclosed. In the high voltage generating circuit a boost node is precharged and boosted by a plurality of pump circuits and then discharged to an output terminal.Where a voltage apparent at the boost node is smaller than a power supply voltage, the voltage apparent at the boost node is elevated to the power supply voltage. Where the voltage apparent at the boost node is larger than the power supply voltage, a current path is prevented from forming between the boost node and the power supply voltage so as to maintain the voltage apparent at the boost node.