NOVELTY - The gas flow path formation elements (21,22) which are arranged between an anode layer (17) and separator (23) and a cathode layer (18) and separator (24) respectively have several ring portions (27) forming through-holes (26) in lathe-cut metals (25). The ring portions have planar surfaces (28a) in contact portions (28) that are arranged in contact with carbon papers (19,20) adhered on the anode and cathode layers respectively.    USE - Gas flow path formation structure for electric power generation cell of fuel cell stack (claimed) such as polymer electrolyte fuel cell stack.    ADVANTAGE - The planar surfaces of contact portions in ring portions are arranged in contact with carbon papers adhered on anode and cathode layers. Thus damage of carbon papers by contact portions can be prevented, penetration of carbon paper fragments into gas channel can be avoided and effective area of gas flow path can be increased. The fuel gas and oxidizing agent gas can be supplied uniformly to anode and cathode layers, gas supply amount can be increased, electric power generation efficiency can be improved, thickness of gas flow path formation elements can be enlarged, current collection efficiency can be improved with smooth flow of electricity from carbon papers, the molding apparatus can be simplified and the planar surfaces of contact portions can be molded easily.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) gas flow path formation element manufacturing method;    (2) molding apparatus for manufacturing gas flow path formation element;    (3) electric power generation cell of fuel cell stack; and    (4) method of manufacturing electric power generation cell of fuel cell stack.    DESCRIPTION OF DRAWING(S) - The drawing shows a longitudinal cross-sectional view of the fuel cell stack comprising electric power generation cell provided with gas flow path formation elements.    Anode layer (17)    Cathode layer (18)    Carbon papers (19,20)    Gas flow path formation elements (21,22)    Separators (23,24)    Lathe-cut metals (25)    Through-holes (26)    Ring portions (27)    Contact portions (28)    Planar surfaces (28a)