A metallic material of the invention which comprises, in mass %, C: not more than 0.2%, Si: 0.01-4%, Mn: 0.05-2%, P: not more than 0.04%, S: not more than 0.015%, Cr: 10-35%, Ni: 30-78%, Al: not less than 0.005% but less than 4.5%, N: 0.005-0.2%, and one or both of Cu: 0.015-3% and Co: 0.015-3%, with the balance substantially being Fe, and of which the value of 40Si+Ni+5Al+40N+10 (Cu+Co), wherein the symbols of elements represent the contents of the respective elements, is not less than 50 and has excellent corrosion resistance in an environment in which metal dusting is ready to occur and, therefore, can be utilized as or in heating furnace pipes, piping systems, heat exchanger pipes and so forth to be used in a petroleum refinery or in petrochemical plants, and can markedly improve the equipment durability and safety.