A solid electrolytic capacitor element that includes a valve metal substrate having an anode terminal region and a cathode-forming region; a dielectric layer on the cathode-forming region; a solid electrolyte layer on the dielectric layer; a current collector layer on the solid electrolyte layer; and a masking member between the anode terminal region and cathode-forming region to insulate the substrate from opposite polarity. The masking region includes a first coating portion, an exposed region exposing the dielectric layer, and a second coating portion arranged in this order starting from a boundary between the anode terminal region and the cathode-forming region towards the anode terminal region. The solid electrolyte layer covers the first coating portion and at least a portion of the exposed region.