NOVELTY - The tubular fuel cell for increasing power density per unit area of the tubular fuel cell, comprises an inner current collector (5), a membrane-electrode assembly (6a), and seal portions placed at axial end portions of the assembly. The membrane-electrode assembly has an inner catalyst layer (2a) placed on the inner current collector, an electrolyte membrane (1) placed on the inner catalyst layer, and an outer catalyst layer (2b) placed on the electrolyte membrane. Axial end faces of the inner catalyst layer are denoted as A1 and A2.    USE - Useful for increasing power density per unit area of the fuel cell.    ADVANTAGE - The tubular fuel cell is compact in size and can be manufactured in simple method, and enables power generation at a high power density and prevents undesired power generation.    DETAILED DESCRIPTION - The tubular fuel cell for increasing power density per unit area of the tubular fuel cell, comprises an inner current collector (5), a membrane-electrode assembly (6a), and seal portions placed at axial end portions of the assembly. The membrane-electrode assembly has an inner catalyst layer (2a) placed on the inner current collector, an electrolyte membrane (1) placed on the inner catalyst layer, and an outer catalyst layer (2b) placed on the electrolyte membrane. An axial length of the outer catalyst layer is shorter than an axial length of the electrolyte membrane and the inner catalyst layer. Axial end faces of the inner catalyst layer are denoted as A1 and A2. Axial end faces of the electrolyte membrane with respect to the axial end face A1 and A2 are denoted as B1 and B2 respectively. Axial end face of the outer catalyst layer with respect to the axial end face A1, B2 and A2, B2 are denoted as C1 and C2 respectively. The end face C1 and C2 are closer to an axial center of the fuel cell than the end faces A1, B1 and A2, B2 located respectively. One of the seal portions is disposed between the end faces A1, B1 and C1, and the other of the seal portions is disposed between the end faces A2, B2 and the end face C2. The seal portions are disposed to cover the end faces C1, C2 and are made of a two-component adhesive.    DESCRIPTION OF DRAWING(S) - The diagram shows the tubular fuel cell:    Electrolyte membrane; (1)    Inner catalyst layer; (2a)    Outer catalyst layer; (2b)    Inner current collector; (5)    Membrane-electrode assembly. (6a)