The charge pump is provided, which comprises a power supply circuit and a frequency control circuit. The power supply circuit comprises at least one electric energy storage element, and charges the at least one electric energy storage element for producing a supply voltage. The frequency control circuit is coupled to the at least one electric energy storage element, and outputs an operating signal to the power supply circuit. The frequency control circuit adjusts, an operating frequency of the operating signal in according to the electricity stored in the at least one electric energy storage element for controlling charging of the at least one electric energy storage element to increase the electricity of the at least one electric energy storage element.