Abstract: There is disclosed a process wherein impurities are removed from hydrofluoric acid by converting the highly volatile arsenic compounds into a compound with a very high boiling point. The process comprises the following steps: input of distilled hydrofluoric acid, which contains arsenic, into a reactor and cooling down to a temperature below room temperature; oxidation of the arsenic contained in the hydrofluoric acid in the form of arsenic trifluoride with an oxidizing agent in the presence of a surplus of potassium ions coming from potassium bifluoride in order to obtain an arsenic complex which is both stable and of high boiling point; halting the cooling of the reaction mixture and continuation of the stirring for a period of from 1-24 hours, permitting the mixture to remain quiescent to permit deposition; and finally distilling of the hydrofluoric acid at a temperature below reflux conditions, whereupon the arsenic complex formed during the oxidation reaction is removed from the hydrofluoric acid.