Provided are a polycrystalline silicon ingot casting mold and a method for producing a polycrystalline silicon ingot casting mold, with which high-quality silicon ingots can be obtained at high yields by minimizing sticking with the surfaces of the silicon ingot casting mold, and losses and damages that occur when solidified silicon ingot is released from the mold. The method for producing a polycrystalline silicon ingot casting mold having a release layer, including: forming a slurry by mixing a silicon nitride powder with water, coating the surface of the mold with the slurry, and heating the mold at 400 to 800° C. in an atmosphere containing oxygen, after coating the slurry.