SOLID ELECTROLYTE FUEL CELL

To provide a solid oxide fuel cell system capable of efficiently and simply controlling a low speed fuel cell module and a high speed inverter. The invention is a solid oxide fuel cell system (1), comprising: a fuel cell module (2), a fuel flow regulator unit (38), a control section (110) comprising a first power demand detection circuit (110a) for controlling the fuel supply amount and for setting the value of current extractable from the fuel cell module; an inverter (54) for extracting current from fuel cell module (2); and a second power demand detection circuit (111a); and having an inverter control section (111) for controlling the inverter independently from the fuel cell controller so that a current responsive to power demand is extracted from the fuel cell module in a range not exceeding the extractable current value input from the fuel cell controller.