NOVELTY - Preparation of high temperature-constant metal catalysts or catalyst substrates from intermetallic compounds, basic alloy or basic superalloy with a component (A) and a component (B), comprises transforming intermetallic compounds or alloy to a catalytic substance on a metallic base passivated by a upper-laminar layer; and transforming intermetallic compounds or alloy to a high temperature-constant metal catalyst substrate.    USE - The catalyst is useful in a catalytic process such as reforming reactions, preferably steam reforming reaction of hydrocarbons, dry reforming reaction of hydrocarbons, in autothermal reforming reaction of hydrocarbons, for the production of hydrogen, synthesis gas, carbon monoxide, endogas, inert gas, for splitting of ammonia to hydrogen and nitrogen and for methanizing carbon monoxide or carbon dioxide. The intermetallic compounds or alloy with (A) is used for producing the high temperature-constant metal catalysts or high temperature-constant metal catalyst substrates (claimed). The formed metallic materials are useful as pins, wool, splinters, spirals or feathers/springs.    ADVANTAGE - The metal catalyst or metal catalyst substrates are high temperature-constant (claimed). The metals can be easily brought into a form of fabrics, fibers or other possible structures to give a high geometrical surface.    DETAILED DESCRIPTION - Preparation of high temperature-constant metal catalysts or catalyst substrates from intermetallic compounds, basic alloy or basic superalloy with a component (A) and at least a component (B), where (A) is catalytically effective component, comprises transforming intermetallic compounds or alloy to a catalytically effective substance on a metallic base passivated by a upper-laminar layer; and transforming intermetallic compounds or alloy to a catalytically effective high temperature-constant metal catalyst substrate, where the high temperature-constant metal catalysts is used as catalyst and the high temperature-constant metal catalyst substrate is used as catalyst substrate.