To solve the problem that a ball of a floating body object is bound by a chain or a strap within a fixed distance, magnets are bound at two or four positions therein, the floating body object and the magnets are put in a doughnut-shaped tube, on the other hand, the inside of the tube is filled with water, coils are wound around the outside of the tube and react with the floating body object and the magnets to generate electricity, therefore, it is necessary to rotate the floating body object and the magnets and further, since the floating body object is under delicate stability, it is necessary to rotate the floating body object in one direction.

Any motive force may be required for rotating a floating body object, thereby proposing natural power as the motive force. In an example utilizing air as the motive force, the wind received from the front by traveling of an automobile, motorcycle, bicycle or train is received in one direction and hits the floating body object to utilize the power of the wind, thereby rotating the floating body object and magnets. In such a case, it is necessary to applying coating to the magnets or the binding chain for preventing trouble caused by being wet with water.