A fuel cell system and an operating method thereof upon restart after an emergency stop of the fuel cell can be reduced an adverse effect which acts on the fuel cell.
And A fuel cell (1), a fuel gas supply device, an oxygen-containing gas supply device, a memory device operation stop of the fuel cell (1) stores which one normal stop or emergency stop, comprising at least a control device for controlling the operation of the fuel gas supply system and the oxygen-containing gas supply unit and (10), said control device (10), when the restart after the stop of the operation of the fuel cell (1), If the operation stop of the fuel cell stored in the storage device (1) was an urgent stop, supplied to the fuel cell (1) than when restarting after shutdown of the fuel cell (1) was normal stop It is the way to reduce the fuel gas supply amount, to control the fuel gas supply system.