To facilitate the application of mortar by reducing the mount of mutual overlap of lath nets at each corner of the lath net, and to prevent the appearance of cracks on a mortar surface.

The rectangular lath net A is fixed to a lath-fixing substrate plate in such a manner that edges along four sides overlap one another. Two of four rectangular crossed surface parts Ac, where a longitudinal edge surface part Aa with a predetermined width, and a lateral edge surface part Ab with a predetermined width, overlapping another lath net A, cross each other, are cut; the two rectangular crossed surface parts are cut in one place; and the outside of each of diagonal lines of them is cut.