A capacitor multiplier including a capacitor, a first voltage follower, a first impedance element, and a second impedance element is provided. The input terminal of the first voltage follower is electrically connected to the first terminal of the capacitor. Wherein, the voltage level of the output terminal of the first voltage follower changes along with the voltage level of the input terminal thereof. The first terminal of the first impedance element is electrically connected to the first terminal of the second impedance element. The second terminal of the first impedance element is electrically connected to the first terminal of the capacitor. The second terminal of the second impedance element is electrically connected to the output terminal of the first voltage follower.