A charge pump circuit comprises a plurality of capacitors (3, 5; 12a SIMILAR 12e) for generating a charged-up voltage. An oscillation circuit (130; 100) causes an oscillation to alternately charge these charge-up capacitors. A monitoring circuit (110, 120; 13 SIMILAR 15) detects an electrical potential of the charge-up capacitors. An oscillating condition of the oscillation circuit is controlled based on the electrical potential of the charge-up capacitors. <IMAGE>
