Fuel cell system

A fuel cell system comprising:

• a fuel cell that generates electric power by an anode gas supplied to an anode and a cathode gas supplied to a cathode;
• a cathode supply path that supplies the cathode gas via a humidifier to the fuel cell;
• a cathode supply bypass path that bypasses the humidifier and supplies the cathode gas to the fuel cell;
• a bypass supply valve that is provided on the cathode supply bypass path;
• a temperature acquisition portion that acquires an ambient temperature of the fuel cell;
• and
• a control device that executes, when the ambient temperature is less than a predetermined temperature at a time of a start of the fuel cell, a warm-up control which sets the fuel cell to an electric power generation state and raises a temperature of the fuel cell to the predetermined temperature or more, and
• executes, after executing the warm-up control, a humidity control which sets the bypass supply valve to a valve open state and supplies the cathode gas that has bypassed the humidifier to the fuel cell.