NOVELTY - A secondary battery-type fuel cell system consists of a fuel generation component (1) for generating fuel gas by chemical reaction and regenerating the chemical reaction by a reverse reaction, and an electric power generation/electrolysis unit having electrolysis function for electrolyzing the product of reverse reaction supplied from the fuel generation component during regeneration of electric power generation function and producing electric power using oxidizing agent gas and fuel gas supplied from the fuel generation component.    USE - Secondary battery-type fuel cell system is used for charging and generation of electric power.    ADVANTAGE - The secondary battery-type fuel cell system has high efficiency and improved supply of the reaction gas.    DETAILED DESCRIPTION - A secondary battery-type fuel cell system consists of a fuel generation component for generating fuel gas by chemical reaction and regenerating the chemical reaction by a reverse reaction, and an electric power generation/electrolysis unit having electrolysis function for electrolyzing the product of the reverse reaction supplied from the fuel generation component during regeneration of electric power generation function and producing electric power using oxidizing agent gas and fuel gas supplied from the fuel generation component. The secondary battery-type fuel cell system circulates gas between the fuel generation component and the electric power generation/electrolysis unit. The fuel cell system is operated using normal operation mode chosen from a starting mode for starting operation of system, a normal operating mode for performing normal operation of system, and a stop mode for stopping the operation of system. The value of electric power output from the electric power generation/electrolysis unit or value of electric power supplied to electric power generation/electrolysis unit is changed temporally, when electric power is produced in the electric power generation/electrolysis unit.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of the structure of secondary battery-type fuel cell system.    Fuel generation component (1)    Fuel cell portion (2)    Container (3)    Piping (5)    Switch portion (6)