A capacitor element includes an anode body including a porous region located at a surface of the anode body, a dielectric layer that covers at least a part of the anode body, and a cathode layer that covers at least a part of the dielectric layer. The anode body includes an anode part and a cathode formation part on which the cathode layer is disposed, the cathode formation part being adjacent to the anode part. At least a part of the porous region of the anode part includes a thin-thickness region that is thinner than the porous region in the cathode formation part, and a metal substrate is stacked on at least a part of the thin-thickness region. The metal substrate is denser than the porous region in the cathode formation part.