A body bias voltage generating circuit includes a current mirror circuit configured to generate and input a target current to a target semiconductor element, the target semiconductor element configured to be set to a turned-on state; and a charge pump circuit including an oscillator configured to output a clock signal based on a result of comparing an output voltage of the target semiconductor element with a reference voltage, and at least one charge pump outputting a body bias voltage to each of a plurality of semiconductor elements, wherein each of the plurality of semiconductor elements is the same as or is the same type as the target semiconductor element.