Abstract: There is provided a fuel cell generating set including (a) a fuel cell, (b) a Lysholm compressor, (c) a gas-liquid separation apparatus condensing humidity generated in the fuel cell into water and retaining the thus-produced water therein, and (d) an injection pump for injecting the water to an intake port of the Lysholm compressor. The water exchanges heat with air under pressure in the Lysholm compressor to thereby cool air to be discharged from the Lysholm compressor by latent heat of vaporization. The water injected from the injection pump seals a leakage path in the Lysholm compressor. The above-mentioned generating set enhances volumetric efficiency and temperature efficiency of a Lysholm compressor, which ensures that the generating set can operate with less power and the generating set can be made smaller in size and lighter in weight. In addition, it is not necessary to supply water to the generating set, because the generating set is self-sufficient with respect to water.