The invention relates to a use of a fluorination gas, and the elemental fluorine (F2) is preferably present in a high concentration, for example, in a concentration of elemental fluorine (F2), especially of equal to much higher than 15% or even 20% by volume, and to a process for the manufacture of a fluorinated benzene derivative starting from benzoic acid derivative by direct fluorination employing a fluorination gas, wherein the elemental fluorine (F2) is preferably present in a high concentration, and subsequent decarboxylation of the benzoic acid hypofluorite derivative obtained by direct fluorination. The process of the invention is also directed to the manufacture of a benzoic acid hypofluorite derivative by direct fluorination of benzoic acid derivative. Especially the invention is of interest in the preparation of fluorinated benzene derivative, final products and as well intermediates, for usage in agro-, pharma-, electronics-, catalyst, solvent and other functional chemical applications.