To obtain driving force and utilize kinetic energy minimizing external force, using a magnet and an electromagnet.

A high-efficient flywheel is obtained as a high-efficient energy utilization device and an energy utilization system, wherein the external energy is minimized in accumulating the kinetic energy, and a magnetic force is utilized using the magnet and the electromagnet, by which damping of the kinetic energy is prevented. In the flywheel, utilizing the magnetic force, it rotates in a fixed direction to obtain the driving force, the flywheel is rotated and at a high speed, to obtain the kinetic energy by inertial force, energy is efficiently converted and accumulated, and electricity is generated when required to obtain electric energy. Energy is utilized by the flywheel which effectively accumulates with lower kinetic energy as compared with the kinetic energy that drives the flywheel of a mere rigid body.