FUEL CELL SYSTEM AND METHOD FOR OPERATING SAME

A fuel cell system of the present invention comprises a supply unit; a hydrogen generator, a fuel cell, a voltage meter, and a controller, wherein the controller is configured to: when the voltage measured by the voltage meter decreases to a first predetermined value by changing an electric power output of the fuel cell, perform control such that a change rate of the electric power output is set lower than a value before the voltage measured by the voltage meter decreases to the first predetermined value, or perform control such that power generation in the fuel cell is stopped, and the change rate of the electric power output is set lower than the value before the voltage measured by the voltage meter decreases to the first predetermined value, when the electric power output is changed during an operation of the power generation resumed after the power generation in the fuel cell is stopped.