A voltage detection circuit for a secondary battery. A secondary battery is composed of a plurality of battery blocks (B1) to (B3), and is connected to a flying capacitor (C1) via input side sampling switches (SW1) to (SW3). The flying capacitor (C1) is connected to a differential amplifier circuit (10) via output side sampling switches (SWa) and (SWb). A feedback capacitor (C2) is connected to an inverting input terminal of the differential amplifier circuit (10) to form an integrator circuit, which reduces the capacitance of the flying capacitor (C1).