This chapter covers the electromagnetic inductionElectromagnetic induction, which is one of most important phenomena that describe electric and magnetic fieldsMagnetic field varying with time. The electromotive forceElectromotive force appears to induce a currentCurrent in a closed circuit in such a way as to reduce any change in the magnetic fluxMagnetic flux penetrating it. This is Faraday’s lawFaraday’s law. As a result, the electric fieldElectric field is no longer irrotational and has a vortex caused by a variation in the magnetic flux densityMagnetic flux density with time. Faraday’s lawFaraday’s law is rewritten for the local relationship called the motional lawMotional law, E = v × B, in terms of the velocity v of a material in a space with a magnetic flux densityMagnetic flux density B. The magnetic energyMagnetic energy, which is covered in Chap. 8 , is estimated again from the electric energyElectric energy that the electric power sourceElectric power source supplies under the electromagnetic inductionElectromagnetic induction. Finally, the skin effectSkin effect is discussed in association with the electromagnetic inductionElectromagnetic induction.