The present invention is an average particle size of 0.04μm or more and an aspect aspect ratio is small, a large round-shaped zinc peroxide particles having a particle diameter with excellent performance in terms of near spherical shape, which is obtained by baking it ratio is small, the particle size distribution is sharp rounded shaped zinc oxide particles, a process for their preparation, and cosmetics containing such a rounded shaped zinc oxide particles, to provide a heat radiating filler. A mean particle diameter of more than 0.04μm, the average particle size obtained by the aspect ratio of pyrolysis of 2.0 or less roundish zinc peroxide particles and the roundish zinc peroxide particles 0. 04μm or more, an aspect ratio of 2.0 or less roundish zinc oxide particles. .BACKGROUND【課題】平均粒子径が０．０４μｍ以上であり、アスペクト比が小さく、球状形状に近いという点で優れた性能を有する粒子径の大きい丸み状過酸化亜鉛粒子、それを焼成して得られるアスペクト比が小さく、粒度分布がシャープな丸み状酸化亜鉛粒子、それらの製造方法、及び、そのような丸み状酸化亜鉛粒子を配合した化粧料、放熱性フィラーを提供する。【解決手段】平均粒子径が０．０４μｍ以上、アスペクト比が２．０以下の丸み状過酸化亜鉛粒子及び当該丸み状過酸化亜鉛粒子を熱分解することによって得られた平均粒子径が０．０４μｍ以上、アスペクト比が２．０以下の丸み状酸化亜鉛粒子。【選択図】図１
