NOVELTY - Preparing alumina (I), comprises: mixing an aqueous medium (20-300 parts by weight) with a first dry powdery aluminum hydroxide (100 parts by weight) prepared by an aluminum alcoholate process to give a wet powdery aluminum hydroxide; drying the wet powdery aluminum hydroxide by an agitation drying system to give a second dry powdery aluminum hydroxide; and calcining the second dry powdery aluminum hydroxide.    USE - (I) is useful in industry as a raw material: of ceramic materials; of high density sintered bodies; and of single crystal sapphire, abrasives and a wide variety of fillers. (I), preferably alpha alumina is useful: as a raw material for making a porous film, which is useful for coating the surface of an electrode of a secondary lithium ion battery; as a raw material for preparing a phosphor; as a raw material for producing an alpha alumina sintered body. The alpha alumina sintered body is useful for: applications which require high strength, such as a cutting tool and bioceramics; components of apparatuses for producing semiconductors such as a wafer handler, heat-conductive fillers, translucent tubes of a sodium lamp, a metal halide lamp; and ceramic filters for removal of solid substances contained in gases such as exhaust gas, for filtration of aluminum molten metal, and for filtration of food and beverages such as beer, where the ceramic filter is a permselective filter for selectively permeating hydrogen in a fuel cell or selectively permeating gas components (e.g. carbon monoxide, carbon dioxide, nitrogen and oxygen) generated during petroleum refining. The alpha alumina sintered body is useful as a catalyst carrier for carrying a catalyst component on the surface of the permselective filter.    ADVANTAGE - The process provides (I) having a high bulk density at a high volume efficiency and less coarse agglomerated particles. (I) provides a porous film with improved heat resistance and electrical insulation properties. (I) improves the safety of the battery in case of internal short circuits. (I) has improved mechanical resistance.