An inspection method of a present electrical storage device (1) includes: constituting a circuit (3) with the electrical storage device (1) being charged and a power supply (4), and passing a current (IB) by the power supply (4) to the circuit (3) in a direction of charging or discharging the electrical storage device (1); and in passing the current (IB), determining the quality of the electrical storage device (1) based on a converging state of the passing current (IB). In passing the current (IB), an output voltage (VS) of the power supply (4) is changed from an initial value with the passage of time.