A power storage apparatus (100, 200, 300A) having a plurality of power storage elements, the apparatus comprising: 2 n, wherein n is an integer not less than 2, power storage elements (B1 to B(2 n)) connected in series; voltage measuring means and current measuring means for respectively measuring voltage and current of a first power storage unit consisting of first to 2 n-1 -th power storage elements (B1 to B(2 n-1)) and a second power storage unit consisting of 2 n-1 +1 -th to 2 n -th power storage elements (B(2 n-1 +1) to B(2 n)) among the 2 n power storage elements (B1 to B(2 n)); a first switch and a second switch connected in series at both ends of the first to 2 n -th power storage elements (B1 to B(2 n)); a first inductor, on which an inter-terminal voltage of either one of the first power storage unit or the power storage unit selected through ON/OFF actions of the first switch and the second switch is applied; and a control section (C2 n) configured to switch ON/OFF of the first switch and the second switch at a predetermined timing, wherein the control section (C2 n) switches the first switch and the second switch to sequentially form a closed circuit including the first inductor and either one of the first power storage unit or the second power storage unit and a closed circuit including the first inductor and the other one of the first power storage unit or the second power storage unit,and measures and compares magnitudes of impedances of the first power storage unit and the second power storage unit using the voltage measuring means and the current measuring means to identify the power storage unit having a larger impedance. 2 n, wherein n is an integer not less than 2, power storage elements (B1 to B(2 n)) connected in series; voltage measuring means and current measuring means for respectively measuring voltage and current of a first power storage unit consisting of first to 2 n-1 -th power storage elements (B1 to B(2 n-1)) and a second power storage unit consisting of 2 n-1 +1 -th to 2 n -th power storage elements (B(2 n-1 +1) to B(2 n)) among the 2 n power storage elements (B1 to B(2 n)); a first switch and a second switch connected in series at both ends of the first to 2 n -th power storage elements (B1 to B(2 n)); a first inductor, on which an inter-terminal voltage of either one of the first power storage unit or the power storage unit selected through ON/OFF actions of the first switch and the second switch is applied; and a control section (C2 n) configured to switch ON/OFF of the first switch and the second switch at a predetermined timing, wherein the control section (C2 n) switches the first switch and the second switch to sequentially form a closed circuit including the first inductor and either one of the first power storage unit or the second power storage unit and a closed circuit including the first inductor and the other one of the first power storage unit or the second power storage unit,and measures and compares magnitudes of impedances of the first power storage unit and the second power storage unit using the voltage measuring means and the current measuring means to identify the power storage unit having a larger impedance.