A fuel cell of the present invention comprises a power generating cell (C), which has at least two surfaces, a fuel gas being supplied through one of the surfaces and oxygen being supplied through the other surface, thereby generating electric power, a cell holder (6) that holds the power generating cell (c) to face the one of the surfaces inward, whereby forming an inner space together with the power generating cell (C), and a fuel generating section (B) that is arranged in the inner space of the cell holder (6) and generates the fuel gas.