To provide a solid oxide fuel cell device capable of smooth transition from a startup state to an electrical generating state. The present invention is a solid oxide fuel cell device (1) for generating electricity, having a fuel cell module (2); a reformer (20), a fuel supply device (38); a water supply device (28), a generating oxidant gas supply device (45), and a controller (110) for controlling the fuel supply device and water supply device at the time of startup when the fuel cell module solid oxide fuel cell unit is raised to a temperature at which electrical generation is possible; whereby the controller controls the fuel supply device during the SR operation such that electrical generation is started after reducing the fuel supply flow rate prior to starting electrical generation.