Regeneration method for removal liquid, and regenerated removal liquid

The method for regenerating a removal liquid comprises: a step for removing a nickel-chromium-containing layer from a substrate provided with the nickel-chromium-containing layer and a copper-containing layer using a removal liquid when manufacturing a printed wiring board by a semi-additive method; a step for collecting the used removal liquid; and a step in which the removal liquid recovered in the recovery step is brought into contact with a chelate resin having a functional group represented by formula (1). In formula (1), a plurality of Rs are the same divalent hydrocarbon group having 1-5 carbon atoms. Some of hydrogen atoms contained in the hydrocarbon group may be substituted by halogen atoms. [Chemical Formula 1] 除去液的再生方法包括：在利用半加成法制造印刷线路板时，使用除去液从具备镍铬含有层和铜含有层的基板中除去所述镍铬含有层的工序；回收已使用的所述除去液的工序；以及使在所述回收工序中回收的除去液与螯合树脂接触的工序，所述螯合树脂具有由下述式(1)所表示的官能团。式(1)中，多个R是相同的碳原子数为1～5的2价烃基。所述烃基所具有的氢原子的一部分可以被卤素原子取代。[化学式1]