Provided is a flywheel engine (100) provided with horizontal and vertical flywheel gear plates (E, E1), which are coupled with a prime mover, to which a balanced increased load is inputted. The flywheel engine serves as a prime mover such as an elevator or building generator or lift pump, or a propulsion engine of a vehicle (train, car or bicycle) and is configured so as to combine a screw rotation flywheel plate (B) as an independent engine, and the gear plates (E, E1).