Patent ID: 7419927

Claim:
A ceramic electronic device having a dielectric layer, wherein: said dielectric layer includes as its main component, a component expressed by a composition formula of Ba m TiO 2 +m, wherein “m” satisfies 0.995≦m≦1.010 and a ratio of Ba and Ti satisfies 0.995≦Ba/Ti≦1.010, and a subcomponent including an oxide of Al; said dielectric layer includes a segregation phase, and said segregation phase includes an oxide of Al; a content of said oxide of Al is 4.0 moles or less, but more than zero moles in terms of Al 2 O 3 with respect to 100 moles of said maincomponent; and a C.V. value of a distribution of Al 2 O 3 calculated by a formula (1) below from standard deviation σ of detection strength and an average detection strength x of the Al 2 O 3 distribution in said dielectric layer is 100 or lower; wherein the formula (1) for C.V. value is (standard deviation σ of detection strength/an average detection strength x)×100; said dielectric layer further includes a first subcomponent including at least one compound selected from MgO, CaO, BaO, and SrO; a second subcomponent including an oxide silicon as a main component; a third subcomponent including at least one compound selected from V 2 O 5 , MoO 3 and WO 3 ; and a fourth subcomponent including an oxide of R, wherein R is at least one element selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; and ratios of the respective subcomponents with respect to 100 moles of said main component are first subcomponent: more than 0 to 3.0 moles second subcomponent: 2 to 10 moles third subcomponent 0.01 to 0.5 mole, and fourth subcomponent 0.5 to 7 moles, wherein the number of moles of the fourth subcomponent is a ratio of R alone.