Abstract: A piezoelectric thin film device (10) comprising a substrate (12) having a vibration space (20), and a piezoelectric lamination structure (14) formed on the upper surface of the substrate, the piezoelectric lamination structure comprising a piezoelectric film (16) and a lower electrode (15) and upper electrode (17) which are formed on opposite surfaces thereof, respectively, the vibration space (20) being so formed as to allow the vibration of a vibrating section (23) constituted by including at least part of the piezoelectric lamination structure (14) and part of an insulating layer (13). The vibrating space (20) is composed of a first via hole (21) formed from the lower surface of the substrate (12) toward the upper surface thereof so as to form an intermediate surface (25) in the substrate, and a second via hole (22) formed from the intermediate surface (23) toward the upper surface of the substrate so as to be positioned inside the first via hole (21) as seen vertically.

Abstract: 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 ?m, and the mean particle size of the additive component particles is made not more than 0.31 ?m. 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 ?m are provided.

Abstract: 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 &mgr;m, and the mean particle size of the additive component particles is made not more than 0.31 &mgr;m. 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 &mgr;m are provided.