A power storage apparatus provided with a capacitor module and a power storage control circuit is connected between a generator and an electrical load. The capacitor module includes a plurality of capacitors and a plurality of switching devices which are connected in series with the capacitors, respectively, the capacitors and the switching devices together constituting a plurality of series circuits which are connected parallel to each other. When starting up the generator, the power storage control circuit controls only the specified switching device to become ON in order to quickly charge the capacitor which is connected in series with the switching device so that a voltage of the capacitor module is increased and a power source for starting up the generator is produced as high speed.