A thrust generating apparatus which is positioned under water and configured to generate a thrust by ejecting water includes a duct-shaped stator provided with a plurality of armature coils, and a plurality of ring-shaped rotors which are arranged radially inward of the stator and provided with permanent magnets respectively corresponding to the plurality of armature coils, wherein the plurality of rotors are arranged in series in a rotational axis direction thereof and each of the rotors has a propeller vane protruding radially inward. A thrust generating apparatus is capable of outputting a high driving power without increasing a propeller diameter.