The present invention addresses the problem of providing a treatment method whereby the flatness of an object of interest having a metal layer can become superior when the method is applied to the object of interest. The present invention also addresses the problem of providing a treatment solution for an object of interest. The method for treating an object of interest according to the present invention comprises step A for subjecting an object of interest having a metal layer to an oxidation treatment to form a metal oxide layer and step B for bringing the object of interest obtained in step A into contact with a treatment solution to dissolve and remove the metal oxide layer, in which the treatment solution comprises an organic solvent and an acidic compound and the content of the organic solvent is 50% by mass or more relative to the whole mass of the treatment solution.
展开▼
