An apparatus for rotating a shaft by using an electromagnet is provided. Permanent magnets are placed around a shaft to rotate with the shaft, and an electromagnet is placed outside the circumference of the permanent magnets, and a device for activating electromagnet is placed. Two secondary cell batteries are used to activate the electromagnet and the electromagnet makes the permanent magnets rotate. The secondary cell batteries are charged using back-emf which occurs in the electromagnet. Coils are placed around the circumference of the permanent magnets and the rotating permanent magnets generate electricity to the coils.