To provide a dielectric ceramic composition having a high dielectric constant, i.e., 3,000 or more, at elevated temperatures at or above 150° C. and having a practically sufficient relative dielectric constant at an applied DC electric field of 2 V/μm, and to provide a dielectric device including such a dielectric ceramic composition, a dielectric ceramic composition is a composite oxide represented by formula (1): {[(BisNat)a(BiuKv)bBac]1-dNad}xTi1-dNbdO3  (1) where a, b, c, d, s, t, u, v, and x are numbers satisfying the following conditions: 0.20≦a (0.80−a)/2 a+b+c=1 0.02≦d