Abstract: The invention has as its object a method for simultaneously concentrating and purifying phosphoric acid. It consists in bringing into contact, in a tower, the acid to be concentrated and purified divided into fine droplets with a current of hot gases and in collecting, at the bottom of the tower, the concentrated and purified acid. Previously, the acid has been mixed, with water and with a fraction of the said concentrated and purified acid. The invention is implemented for the producing of phosphoric acid having a very low fluorine content, suitable for being used for the synthesis of phosphate foodstuffs.