A method for producing an alkali metal from a salt of the alkali metal soluble in a solvent, comprises the following steps of: (a) performing a first electrolysis in a first electrolysis cell (1) comprising an anode chamber (3) and a cathode chamber (5), wherein the anode chamber (3) and the cathode chamber (5) of the first electrolysis cell (1) are separated by a membrane (7) permeable to alkali metal cations, wherein the salt of the alkali metal dissolved in the solvent is supplied to the anode chamber (3), and a suspension containing sulphur and a second solvent is supplied to the cathode chamber (5), and a mixture containing a second solvent, alkali metal cations, (poly)sulphide anions and further ionic sulphur compounds is removed from the cathode chamber (5);(b) concentrating the mixture containing the second solvent, alkali metal cations, (poly)sulphide anions and further ionic sulphur compounds that was removed from the cathode chamber to form a largely solvent-free alkali metal (poly)sulphide melt; and (c) performing a second electrolysis at a temperature above the melting temperature of the alkali metal in a second electrolysis cell (71) comprising an anode chamber (73) and a cathode chamber, wherein the anode chamber (73) and the cathode chamber of the second electrolysis cell are separated by a solid-state electrolyte conducting alkali metal cations and the alkali metal and (poly)sulphide melt from step (b) is supplied to the anode chamber (73) and sulphur is removed from the anode chamber and liquid alkali metal is removed from the cathode chamber.