Abstract: A method of etching an aluminum foil for electrolytic capacitors, comprising the steps of electrolytically etching an aluminum foil for electrolytic capacitors that has a high cubic texture in an electrolyte containing a chloride to form pits, and enlarging the pits formed in the above step by etching, in which step of forming pits the current density is increased from 0 to a maximum value quickly and then is decreased gradually.

Abstract: The present invention relates to a method of etching aluminum foil for electrolytic capacitors that is improved in etching efficiency, wherein when the aluminum foil is etched by applying alternating current in an electrolytic solution containing chloride ions and the like, the alternating current contains, during the positive half period and the negative half period, two half waves having different waveforms, amplitudes, and applied times, and a rest period between the half waves with the amplitude being 0 or with microcurrent being applied on the positive side or the negative side at at most 1/15 of the maximum amplitude during a half period.