A fuel cell system according to the present invention comprises fuel cell stacks for generating electrical power upon receipt of hydrogen gas and oxidized gas; an end plate to which the fuel cell stacks are fastened; hydrogen system parts (hydrogen inlet valve, regulator, hydrogen pump, gas-liquid separator, hydrogen discharge valve, hydrogen supply pipe, hydrogen discharge pipe, distribution pipes, and connection pipes) for supplying hydrogen gas to the fuel cell stacks; and a stack case for housing at least the fuel cell stacks and hydrogen system parts. The hydrogen system parts are congregated and mounted on the end plate.