Abstract: The power generation system with use of fuel cell, comprises: a cell stack including alternately piled up fuel cell elements and separator plates, each fuel cell element having an anode electrode, an electrolyte and a cathode electrode; a first reforming plate for partially reforming fuel gas to anode gas interposed between arbitrary adjacent separator plates instead of the cell element; a second reformer assembly for reforming the remainder of the fuel gas to the anode gas, the second reformer assembly including a plurality of plate type second reformers; an intermediate holder interposed between the cell stack and the second reformer assembly as they are piled up; an upper and a lower holders for sandwiching the cell stack, the intermediate holder and the second reformer assembly so as to hold them as one unit; and gas passages formed within the cell stack, the second reformer assembly, and the intermediate, the upper and the lower holders.