FUEL CELL SYSTEM

A fuel cell system comprising a fuel cell and a secondary cell as power supply sources to a load, in which, during normal operation, a first control part allows a first converter (boost converter at the fuel cell side) to control an output voltage of the fuel cell and a second control part allows a second converter (boost converter at the secondary cell side) to control an output voltage to a first load side, whereas during an occurrence of an abnormality of the secondary cell, the first control part allows the first converter to control an output voltage thereof and the second control part allows the second converter to control an output voltage to a second load side.