A capacitor of the present disclosure includes a first electrode, a second electrode, and a dielectric. The second electrode is disposed to face a principal surface of the first electrode. The dielectric is disposed between the first electrode and the second electrode. The dielectric is in contact with the first electrode and the second electrode. A surface of the second electrode extends, for example, parallel to a surface of the first electrode, the surfaces each being in contact with the dielectric. An electrical conductivity σx of the dielectric in a particular direction perpendicular to the principal surface and an electrical conductivity σy of the dielectric in a direction perpendicular to the particular direction satisfy a relation σx/σy≤0.01.