NOVELTY - A solid oxide fuel cell device (1) for generating electricity by reacting fuel and electrical generation oxidant gas, comprises: a fuel cell module (2); a fuel supply device; a reformer (20) for reforming fuel; a water supply device for supplying water to the reformer; an electrical generation oxidant gas supply device; and a controller for controlling the fuel supply device and the water supply device during startup procedure.    USE - The solid oxide fuel cell device is useful for generating electricity by reacting fuel and electrical generation oxidant gas (claimed).    ADVANTAGE - The solid oxide fuel cell device is highly efficient, provides sufficient electricity, and is capable of smoothly transitioning from a startup state to an electrical generating state.    DETAILED DESCRIPTION - A solid oxide fuel cell device for generating electricity by reacting fuel and electrical generation oxidant gas, comprises: a fuel cell module furnished with multiple solid oxide fuel cell units; a fuel supply device for supplying fuel used to generate electricity; a reformer for reforming fuel supplied from the fuel supply device and supplying the reformed fuel to the solid oxide fuel cell units, disposed above the solid oxide fuel cell units so as to be heated when fuel not used to generate electricity in the solid oxide fuel cell units is combusted at the top end of the solid oxide fuel cell units; a water supply device for supplying water to the reformer; an electrical generation oxidant gas supply device for supplying oxidant gas for electrical generation to the solid oxide fuel cell units; and a controller for controlling the fuel supply device and the water supply device during startup procedure where the solid oxide fuel cell units in the fuel cell module are raised to a temperature at which electricity can be generated, carrying out within the reformer a steam reforming (SR) operation, which consists of only a steam reforming reaction, then starting the generation of electricity; where the controller controls the fuel supply device to reduce the fuel supply flow rate during the SR operation prior to the start of electrical generation, then starts the generation of electricity.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a solid oxide fuel cell device.    Solid oxide fuel cell device (1)    Fuel cell module (2)    Auxiliary unit (4)    Sealed space (8)    Electrical generating chamber (10)    Fuel cell assembly (12)    Fuel cell stack (14)    Fuel cell unit (16)    Combustion chamber (18)    Reformer (20)    Air heat exchanger (22)    Water supply source (24)    Pure water tank (26)    Water flow regulator unit (28)    Fuel supply source (30)    Fuel flow regulator unit (38)    Air supply source (40)    Reforming airflow regulator unit (44)    Generating airflow regulator unit (45)    First heater (46)    Second heater (48)    Hot water production device (50)    Control box (52)    Inverter (54)