There is an internal voltage generating circuit for providing a stable high voltage by making a response time short. The internal voltage generating circuit includes a charge pump unit for generate a high voltage being higher than an external voltage in response to pumping control signals and a supply driving control signal; a pumping control signal generating unit for outputting the pumping control signals to the charge pump unit based on a driving signal; and a supply driving control unit for receiving the driving signal to generate the supply driving control signal to the charge pump unit.