This chapter covers magnetic phenomena in magnetic materialsMagnetic material. When a magnetic flux densityMagnetic flux density is applied to a magnetic materialMagnetic material, a magnetic momentMagnetic moment due to electron spins appears. This phenomenon is magnetizationMagnetization, and the magnetic momentMagnetic moment is assumed to be produced by virtual small magnetizing currentMagnetizing current loops. Thus, the magnetic flux densityMagnetic flux density is produced by currentsCurrent and magnetizing currentsMagnetizing current in magnetic materialsMagnetic material. We newly define the magnetic fieldMagnetic field that describes only the magnetic flux densityMagnetic flux density produced by the currentCurrent. Magnetic phenomena are generally described in terms of the magnetic flux densityMagnetic flux density and the magnetic fieldMagnetic field. The refraction of the magnetic flux densityMagnetic flux density at an interface between different magnetic materialsMagnetic material is treated. Finally, static electric phenomena and magnetic phenomena are systematically compared in detail.