PURPOSE: To substantially reduce the manufacturing cost of plural types of electrode substrates with the lugs thereof changed as desired by constituting a casting mold with a split mold for casting a substrate grid part and another split mold for casting a substrate lug part, and so placing the lug pattern of the lug part casting split mold as to he freely displacable for the grid pattern of the grid part casting split mold.

CONSTITUTION: A substrate casting mold 1 comprising a hollow cylindrical drum freely rotatable with a rotary axis 2 is constituted with a split mold 1A of cylindrical vessel form occupying the most area of the mold 1 and having large width and an opening at one end for casting the substrate grid part, and a split mold 1B of cylindrical vessel form occupying the remaining area and having small width and an opening at one end. Then, when the casting mold 1 is used for casting substrates having a lug at different positions or substrates having so called inner or outer lugs, the position of the lug pattern (b) of the split mold 1B is deviated to one end of one edge of the corresponding the grid frame of the grid pattern (a) of the split mold 1A and coupled to this mold 1A, and set with a securing fitting 3. Then, a casting process is started, thereby manufacturing a substrate having a lug. In the case of a substrate with an inner lug, the pattern (b) is located further inside from the one end before a casting process.