To provide a thin film capacitor having high flexibility. A thin film capacitor includes: a metal foil having a roughened upper surface; a dielectric film covering the upper surface of the metal foil and having an opening through which the metal foil is partly exposed; a first electrode layer contacting the metal foil through the opening; and a second electrode layer contacting the dielectric film without contacting the metal foil. The particle diameter of crystal at a non-roughened center part of the metal foil is less than 15 μm in the planar direction and less than 5 μm in the thickness direction. This can not only enhance the flexibility of the metal foil to reduce a short-circuit failure in a state where the thin film capacitor is incorporated in a multilayer substrate but also enhance positional accuracy.