CONTROL FOR A FUEL CELL

A fuel cell system has a fuel cell that includes at least one cell with an electrolyte membrane, an index value acquirer and a controller. The index value acquirer obtains a temperature index value correlated to temperature of a short circuit area in each cell. The controller controls a control parameter of the fuel cell affecting the temperature of the short circuit area, such that the temperature index value is within a predetermined range set to make the temperature of the short circuit area lower than a decomposition temperature of the electrolyte membrane.