The purpose of the present invention is to provide a molded inorganic-fiber object which is excellent in terms of scale resistance, thermal shock resistance, and mechanical shock resistance and which is inhibited from shrinking when heated to high temperatures. The molded inorganic-fiber object is obtained by impregnating a needled blanket of inorganic fibers with a liquid substance which contains a precursor of a spinel compound represented by the general formula MgxAlyO4 (wherein the y/x atomic ratio is 2 or higher), thereafter drying the impregnated blanket, and burning the dried blanket to convert the precursor to the oxide.
