A submarine boat provided with a fuel cell (30) for power generation by supply of hydrogen and oxidizing agent, a hydrogen generating device (10) for generating a gas containing hydrogen to be supplied to the fuel cell, and propelling device driven by electricity generated by the fuel cell, characterized in that the hydrogen generating device is to generate a gas containing hydrogen by decomposing a fuel containing an organic compound, comprising a partition membrane (11), a fuel electrode (12) provided on one surface of the partition membrane, means (16) for supplying a fuel containing the organic compound and water to the fuel electrode, an oxidizing electrode (14) provided on the other surface of the partition membrane, means (17) for supplying an oxidizing agent to the oxidizing electrode, and means for generating and collecting the gas containing hydrogen from the fuel electrode.