A pattern electrode having a predetermined pattern and a connecting electrode connected to the pattern electrode are formed on one surface of a single-polarized ferroelectric substance crystal. An electric field is applied across the ferroelectric substance crystal with corona charging or electron beam irradiation from the side of the other surface of the ferroelectric substance crystal. A polarization inversion region having a shape corresponding to the predetermined pattern is thus formed in the ferroelectric substance crystal. The electric field is applied in a state, in which an electrical insulating material is located on the other surface of the ferroelectric substance crystal and at a position corresponding to at least a position of a certain area of the connecting electrode.