In electron holography, electron holograms are characterized by specimen images and interference fringes superimposed thereon. This characterization is essentially the same as that used in 2D-image data treatments in a fringe analysis method. Utilizing this method several phase reconstruction methods have been introduced; among these, the phase-shift method is most advanced for electron holography. In this paper we discuss the principle of the phase-shift method, its optical systems and algorithms together with applications to magnetic materials analysis.