Abstract: A method is described of making a catalytic combustion type gas detector, the sensitivity of which to alcohol vapors and to tobacco fumes is decreased by utilizing a mixture of powders. The mixed powders is composed of at least one metal oxide selected from TiO.sub.2, ZrO.sub.2, Y.sub.2 O.sub.3, HfO.sub.2, CeO.sub.2, La.sub.2 O.sub.3, NiO Cr.sub.2 O.sub.3 and a substance which presents an N-type semiconductor characteristic by gas adsorption. The mixture is coated directly on a wire coil of Pt or the like and a current is applied to the metal wire coil in an oxidizing atmosphere to sinter the coated mixed powder thereon.