Abstract: An electrolytic capacitor having very thin spacer layers is produced by a process in which at least two of the surfaces of an anode valve action metal foil and a cathode metal foil are coated with a photosensitive polymer resin solution; the resultant photosensitive polymer resin solution layers are solidified; the solidified photosensitive polymer resin coatings are masked with a negative or positive masking film having a desired pattern and irradiated with an actinic radiation to partly harden the photosensitive polymer resin coatings in accordance with the masking pattern; after removing the masking film, the irradiated photosensitive polymer resin coatings are developed with a developing liquid to provide spacer layers consisting of hardened portions of the photosensitive polymer resin coatings; the anode and cathode metal foils having the spacer layers are superposed on each other in such a manner that at least one spacer layer is located between the superposed anode and cathode metal foils and at least