Disclosed is a silicon ingot manufacturing vessel capable of preventing external spilling of a silicon melt and capable of high-yield manufacturing of high-quality silicon ingots. The disclosed silicon ingot manufacturing vessel is used when solidifying a silicon melt and growing a silicon polycrystal, and is provided with a box-shape vessel main body dividably assembled from a bottom plate and multiple side plates, and a mold release material formed on the inner surface of said vessel main body. The vessel main body is configured by a porous body comprising one of silicon nitride, silicon carbide, and alumina, or a porous body which combines two or more of these, and the mold release material is configured from silicon nitride. Further, the open porosity of the porous body configuring the vessel main body is 10-40%. Because the mold release material is formed robustly on the inner surface of the vessel main body, damage to the mold release material caused by stress accompanying volume expansion during solidification of the silicon is effectively prevented.