Capacitor including a capacitance forming part having a metal porous body, a dielectric film, and a conductive film

A capacitor comprising:

• an insulating substrate having a first main surface and a second main surface opposite to the first main surface;
• a capacitance forming part facing the first main surface, the capacitance forming part comprising a conductive metal porous body, a dielectric film covering a surface of the metal porous body, and a conductive film covering the dielectric film;
• a first external connection line that comprises a first via conductor penetrating the insulating substrate from the first main surface so as to reach the second main surface and connected to the conductive metal porous body;
• and
• a second external connection line comprises a second via conductor penetrating the insulating substrate from the first main surface so as to reach the second main surface, and an internal conductor covering the conductive film so as to fill a space inside the capacitance forming part, and the conductive film and the second via conductor are connected with at least the internal conductor interposed therebetween.