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 one other spacer layer is located on at least one of the outside surfaces of the superposed anode and cathode metal foils, to provide a laminate; the laminate is wound into a capacitor element; and then the capacitor element is impregnated with an electrolyte.