Capacitor having coated pores

The invention relates to a capacitor with a layered construction on a base element having open pores with inner pore surfaces. The base element is electrically conductive at least in a part of the inner pore surfaces and therefore forms a continuous electrode. The electrically conductive part of the inner pore surfaces is nanostructured. In the capacitor a layer of a solid body electrolyte is directly arranged on the electrode and an electrically conductive counter-electrode layer forming a counter electrode is directly arranged on the solid body electrolyte. The counter electrode is applied as a thin layer so that within the open pores a continuous free space remains. The invention also relates to a construction element comprising a foam structure which is part of such a capacitor. The invention also relates to a method of manufacturing such a construction element.