A dielectric device includes a first electrode, dielectric film, and second electrode, which are laminated. The dielectric film includes columnar crystals extending in a lamination direction. Provided that “x” denotes a reciprocal (1/μm) of a dielectric film thickness and “y” denotes a dielectric material average crystallite size (nm) calculated by the Scherrer equation, “x” and “y” are located within a quadrilateral having point A (0.10, 5), point B (10, 20), point C (10, 35), and point D (0.10, 10) as vertices. Alternatively, the columnar crystals have an average width of less than 40 nm within a distance range from one tenth to one third of the dielectric film thickness from one electrode to the other and an average width of 40 nm or more within a distance range from one tenth to one third of the dielectric film thickness from the other electrode to the one in the lamination direction.