POWER SUPPLY SYSTEM

An objective of the present invention is to provide a power supply system which enables stabilization of power supply voltages of multiple areas and/or redundancy to be achieved with low costs. A power supply system 1 includes a main battery MB for providing power and a sub-battery SB which is separate from the main battery MB and provides power. The power supply system 1 further includes switching boxes SW1 to SW4 in first to fourth areas Al to A4 as a plurality of power supply areas configured to be supplied with power from the main battery MB and sub-battery SB, the switching boxes SW1 to SW4 switching on/off states of power supplies into the first to fourth areas Al to A4 from the main battery MB and from the sub-battery SB. Furthermore, the power supply system 1 includes a control section 6 for switching control of the on/off states for the switching boxes SW1 to SW4.