An impedance measuring device includes power supply means configured to output an alternating current to a positive electrode and a negative electrode of a laminated battery and detection means configured to detect at least one of an alternating-current potential difference between the positive electrode and an intermediate point of the laminated battery and an alternating-current potential difference between the negative electrode and the intermediate point of the laminated battery. The impedance measuring device includes computation means configured to compute an impedance of the laminated battery on the basis of the alternating-current potential difference detected by the detection means and the alternating current output from the power supply means, and an element having an impedance of a prescribed value necessary to calculate a measurement error of the impedance. The impedance measuring device includes switch means configured to alternately switch a battery connection state for connecting the power supp