Thin film capacitor

1 n 1 n A dielectric device having a dielectric layer and first to nth metal layers (where n is an integer of 2 or greater) in contact with the dielectric layer. At least one of the first to nth metal layers contains a base metal. Interfaces between the first to nth metal layers and the dielectric layer have respective arithmetic mean roughnesses of Rato Ra(nm), while an average value Ram (nm) of the arithmetic mean roughnesses of Rato Ra(nm) and a thickness T (nm) of the dielectric layer satisfy T/Ram ≧1.3.