In production of an electrode for an aluminum electrolytic capacitor, a hydrated film is formed onto an aluminum electrode including a porous layer by immersing the aluminum electrode into a first hydration treatment liquid having a temperature of 80° C. or more in a first hydration treatment step (ST1) and thereafter the aluminum electrode is heated in an atmosphere having a temperature of 150° C. or more and 350° C. or less in a dehydration step (ST2). Subsequently, a hydrated film is formed onto the aluminum electrode by immersing the aluminum electrode into a second hydration treatment liquid having a temperature of 80° C. or more in a second hydration treatment step (ST3) and thereafter chemical formation of the aluminum electrode is performed at 400 V or more and further 600 V or more in a chemical formation step.