FUEL CELL SYSTEM

A fuel cell system includes a fuel cell module and an oxidant gas temperature adjustment device for adjusting a temperature of an oxidant gas supplied to the fuel cell module. The fuel cell module includes a first fuel cell and a second fuel cell. The first fuel cell is at least configured to reform a fuel gas. The fuel cell system includes a temperature control unit for setting a target temperature of the oxidant gas supplied to the fuel cell module such that a temperature of the first fuel cell and a temperature of the second fuel cell do not exceed a prescribed upper-limit temperature and controlling the oxidant gas temperature adjustment device based on of the target temperature, and the temperature control unit calculates the target temperature.