Method of controlling a fuel cell system with reformer

Process for regulating a fuel cell system comprises rinsing a reformer with air during the starting up and the shutting down process; and feeding the synthesis gas and/or waste gas partially to the next fuel cell. The reformer produces a hydrogen-rich synthesis gas from a hydrogen-rich fuel by partial oxidation or autothermal reforming. Preferred Features: During the starting up process in the reformer after rinsing with air, the combustion process is carried out with complete combustion of the fuel and air, and only after reaching the optimum reaction temperature the air, fuel and/or water amount is regulated after the requirements for the partial oxidation or autothermal reforming. The optimum reaction temperature is reached as soon as it provides sufficient heat to vaporize water introduced into the reactor.