Hybrid power supply system

In a hybrid power supply system which includes an electric double layer capacitor (10) having a pair of capacitor terminals (11 and 12), an energy storage (70a), and first and second bidirectional DC/DC converters (30a and 30b), the above-mentioned pair of capacitor terminals of the electric double layer capacitor are connected to a load (60a) through the first bidirectional DC/DC converter and are connected to the energy storage through the second bidirectional DC/DC converter.