PURPOSE: To produce continuously a plate substrate for a lead storage battery having a satinized surface by rotating and running endless belt track type half split casting molds, charging a molten metal through the sprue in the upper part of the assembled mold thereof, and performing casting by a block mold type casting.

CONSTITUTION: Half split casting mold blocks 1 connected like an endless belt track are joined by each two pieces with a suitable device and the assembled mold block is moved leftward. A molten metal is charged through the spure 2 in the upper part formed by the joining and is cast with the casting mold in the block 1. The casting is released when the left block 1 is separated. A mold release agent is coated in the mold in the free turn-back part of the block 1. The plate substrate cast like a continuous belt is coiled after the sprue and fins were removed. Since the substrate is coiled, it is easy to carry and store and permits easy heat treatment.