To eliminate a facing stage using graphite upon the production of a mold.

The conventional silica sand and binder are added to casting sand, and artificial graphite is mixed in 5 to 50% by the weight ratio of the whole so as to prepare casting sand. Using the casting sand, a mold is formed. A molten metal is made to flow from a gate so as to be a casting without applying facing to the mold composed of a lower mold 11, an upper mold 12 and a core 13 composed in this way. In this case, since a facing stage is made needless, an operating time can be reduced, and the dimensional precision of a casting can be improved.