To provide a power supply system which can remove a main component without using a filter in removal of odd harmonic components, can be made simple and small and whose cost can be reduced.

A charging device 1 converting AC voltage being input voltage from an AC power supply 3 into DC voltage being output voltage and giving it to a battery 5 is provided with a transformer 9 to which AC voltage is given. A primary side transformer 91 being an input side of the transformer 9 is provided with a plurality of primary side transformer parts 91a and 91b. A plurality of primary side transformer parts 91a and 91b are in a wire connection relation for mutually negating at least two odd harmonic components in a secondary side transformer 93 being an output side of the transformer 9.