A capacitor that includes: a base material having: a substrate; a first conductive portion on at least one main surface of the substrate; and an insulating-resin layer on a surface of the first conductive portion; a plurality of fibrous conductive cores, a first end portion of each of the plurality of the fibrous conductive cores being in contact with the first conductive portion through the insulating-resin layer; a dielectric layer covering a portion of the plurality of the fibrous conductive cores exposed from the base material; a conductive polymer layer covering the dielectric layer such that gaps are provided in spaces between the plurality of the fibrous conductive cores; and a second conductive portion in contact with the conductive polymer layer at a second end portion of the plurality of the fibrous conductive cores.

A capacitor that includes: a base material having: a substrate; a first conductive portion on at least one main surface of the substrate; and an insulating-resin layer on a surface of the first conductive portion; a plurality of fibrous conductive cores, a first end portion of each of the plurality of the fibrous conductive cores being in contact with the first conductive portion through the insulating-resin layer; a dielectric layer covering a portion of the plurality of the fibrous conductive cores exposed from the base material; a conductive polymer layer covering the dielectric layer such that gaps are provided in spaces between the plurality of the fibrous conductive cores; and a second conductive portion in contact with the conductive polymer layer at a second end portion of the plurality of the fibrous conductive cores.