As a result of considering the electromagnetic force on the premise of the existence of "aether", the following was found. The gravity quantum generated by the contraction of the nucleus flows from the electron cloud in which the electrons exist in pairs and the "aether" moves randomly, to the region where the "aether" of the electron cloud in which the electron exists alone is flowing in one direction. The moment it reaches the region, it changes into two magnetic quantum. The magnetic quantum is generated as a combination of an "aether" vortex rotating in the same direction as the "aether" flow of the electron cloud and a low "aether pressure" part above and below the vortex. After that, the magnetic quantum travels in the vertical direction perpendicular to the previous traveling direction while maintaining the rotation. Therefore, the direction of rotation with respect to the direction of travel of the magnetic quantum is opposite each other. Next, it is assumed that the magnetic quantum that rotates to the right in the direction of travel is the magnetic quantum that is generated from the N pole (N magnetic quantum), and the magnetic quantum that rotates to the left in the direction of travel is the magnetic quantum that is generated from the S pole (S magnetic quantum). And then the generation of magnetic force and the mechanism of action were investigated. As a result, the reason why the magnet exerts a repulsive force on the same magnetic poles and the attractive force acts on different magnetic poles, and the mechanism by which a ferromagnetic material such as iron is attracted to the magnet and the ferromagnetic material itself becomes a magnet were clarified. Therefore the structure and properties of the magnet could be explained theoretically, and the mechanism of generation and action of magnetic force was clarified.