A ceramic powder including ceramic main component particles and additive component particles deposited on the surfaces of the main component particles. The mean particle size of the main component particles is made not more than 1.5 μm, and the mean particle size of the additive component particles is made not more than 0.31 μm. The content of the additive composition particles is made 0.1 to 5 wt % with respect to 100 parts by weight of the ceramic powder. The dispersibility of the additive component particles with respect to the main component particles is improved and the uniformity of the structure is promoted to suppress the occurrence of hetero phases. A multilayer ceramic electronic device having a high insulation breakdown voltage and long life even with a thickness of the dielectric layers of not more than 3 μm are provided.