A solid electrolytic capacitor element that includes a valve metal substrate that has 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; a masking member on the anode terminal region, the masking member partitioning between the anode terminal region and the cathode-forming region and insulating the valve metal substrate from opposite polarity; and a hydrophilic member on a surface of the masking member.