Method for extracting valuable materials from organic compounds contained in waste or chemical elements contained therein, comprising the following consecutive steps: a) mixing the waste with a base, so that a liquid medium is formed, b) heating the medium in a reactor to a temperature of 100°C to 140°C for the hydrolysis of organic compounds contained in the medium, and removing (c) the vapour which is formed, b1) transferring (c) the vapour from the reactor to a washing column, b2) adding sulfuric acid or phosphoric acid (c') to the vapour to form ammonium sulphate(s) or ammonium phosphate(s), wherein a solution is obtained in the bottom of the washing column and the vapour is withdrawn (g) from the head of the washing column, b3) transferring (e) the solution obtained in step b2) to an electrochemical cell with a cathode chamber and an anode chamber and electrolyzing the solution, whereupon in the anode chamber sulphuric acid or phosphoric acid is obtained for step b2), b4) returning (c') the sulphuric acid or phosphoric acid obtained from the anode chamber to the washing column and withdrawing (f) valuable substances formed in the cathode chamber, in particular an ammonia solution, c) transferring (d) the liquid medium remaining in the reactor in step b) to a separation device for separating any solid inorganic phase contained in the liquid medium. a) mixing the waste with a base, so that a liquid medium is formed, b) heating the medium in a reactor to a temperature of 100°C to 140°C for the hydrolysis of organic compounds contained in the medium, and removing (c) the vapour which is formed, b1) transferring (c) the vapour from the reactor to a washing column, b2) adding sulfuric acid or phosphoric acid (c') to the vapour to form ammonium sulphate(s) or ammonium phosphate(s), wherein a solution is obtained in the bottom of the washing column and the vapour is withdrawn (g) from the head of the washing column, b3) transferring (e) the solution obtained in step b2) to an electrochemical cell with a cathode chamber and an anode chamber and electrolyzing the solution, whereupon in the anode chamber sulphuric acid or phosphoric acid is obtained for step b2), b4) returning (c') the sulphuric acid or phosphoric acid obtained from the anode chamber to the washing column and withdrawing (f) valuable substances formed in the cathode chamber, in particular an ammonia solution, b1) transferring (c) the vapour from the reactor to a washing column, b2) adding sulfuric acid or phosphoric acid (c') to the vapour to form ammonium sulphate(s) or ammonium phosphate(s), wherein a solution is obtained in the bottom of the washing column and the vapour is withdrawn (g) from the head of the washing column, b3) transferring (e) the solution obtained in step b2) to an electrochemical cell with a cathode chamber and an anode chamber and electrolyzing the solution, whereupon in the anode chamber sulphuric acid or phosphoric acid is obtained for step b2), b4) returning (c') the sulphuric acid or phosphoric acid obtained from the anode chamber to the washing column and withdrawing (f) valuable substances formed in the cathode chamber, in particular an ammonia solution, c) transferring (d) the liquid medium remaining in the reactor in step b) to a separation device for separating any solid inorganic phase contained in the liquid medium.