Activated magnesium oxide has a large specific surface area and is an important raw material for the preparation of highly functional fine inorganic materials, electronic components, inks, and harmful gas adsorbents. This type of magnesium oxide exhibits very high chemical activity and physical adsorption capacity due to its micronized particles and the large ratio of surface atoms to atoms in the bulk phase. Its excellent sintering properties allow it to be formed into highly dense fine crystalline ceramics or multifunctional magnesium oxide films. Additionally, it has high activity and dispersion, making it easy to compound with polymers or other materials.