Extraction procedure of a film area of a component.

Method for extracting a film zone (7, 10) of a component (1), wherein the component (1) is, firstly, at least one salt bath (13), and then, in another step procedural, at least once in an acid bath (13) with at least a first acid, characterized in that for at least the first acid bath (13) nitric acid (HNO3), phosphoric acid (H3PO4) are used, because for bathing salt (13) sodium hydroxide (NaOH) and potassium hydroxide (KOH) are used, including in the salt bath as oxygen donor Na2O.