Abstract: Disclosed herein are a method of controlling a magnetization easy axis of a ferromagnetic film, an ultrahigh-density, low power, nonvolatile magnetic memory using the control method, and a method of writing information on the magnetic memory. The method includes the step of arranging an electrode layer, a piezoelectric layer and a magnetic layer in a layered structure. Thereafter, voltage is applied to the electrode layer to generate an electric field. Thereafter, lattice change is caused in the piezoelectric layer using the generated electric field. Finally, a magnetization easy axis of the magnetic layer is reversibly switched between in-plane and out-of-plane by exerting stress generated by the lattice change onto the magnetic layer.