A thermite process for producing a metal or alloy by charging a reactor furnace with a mixture primarily containing a powdered metallic oxide and a reducing agent such as powdered aluminum, wherein a batch of the mixture of the starting materials is divided into a plurality of loading lots. The amount of heat generated by each of the loading lots of the starting materials is so regulated that it differs from any of the others and the loading lots are sequentially arranged. The lots are loaded into a furnace to form so may layers for thermite reaction in an ascending order in terms of the level of heat generation.