PURPOSE: To provide the method for casting a metal by using a metal mold capable of improving thermal shock resistance without causing deterioration in thermal conductivity and also to provide an alloy for metal mold for casting.

CONSTITUTION: A metal or alloy is cast by using a cast metal mold composed of an alloy for metal mold for casting having a composition consisting of, by weight, 0.1-1.5% Cr, 0.01-0.5% Zr, and the balance Cu. The above-mentioned alloy for metal mold for casting contains at least one or more kinds among 0.05-3wt.% each of one or more elements selected from the group consisting of Sn, Zn, and Mn, 0.1-2wt.% Ti, 0.1-5wt.% each of one or more elements selected from the group consisting of Fe, Ni, and Co, and 0.001-0.2wt.% each of one or more elements selected from the group consisting of Mg, P, and Pb. By this method, mechanical strength and thermal shock resistance can be improved and deterioration in thermal conductivity can be prevented, and further, the possibility of a risk of cracking in the metal mold at the time of casting can be removed.