PROBLEM TO BE SOLVED: To accurately measure an impedance as a measurement target when the impedance is connected to a capacitor in series.SOLUTION: The impedance measurement circuit includes: an amplifier connected to a measurement target, which amplifies an input AC voltage with a gain according to an impedance as a measurement target and outputs the voltage； and a voltage level setting circuit, which sets a DC voltage level of an output node of the amplifier with a first capacitor being connected between an end of the measurement target and the output node of the amplifier, and with a second capacitor being connected between the other end of the measurement target and the node of a voltage correlating with the input AC voltage.SELECTED DRAWING: Figure 1【課題】測定対象のインピーダンスに直列にキャパシタを接続した場合でも、測定対象のインピーダンスを精度よく測定できる。【解決手段】インピーダンス測定回路は、測定対象に接続され、測定対象のインピーダンスに応じた利得で入力交流電圧を増幅して出力する増幅器と、測定対象の一端と、増幅器の出力ノードと、の間に第１キャパシタを接続し、かつ測定対象の他端と、入力交流電圧に相関する電圧のノードと、の間に第２キャパシタを接続した状態で、増幅器の出力ノードの直流電圧レベルを設定する電圧レベル設定回路と、を備える。【選択図】図１
