Abstract: Method of and apparatus for leaching copper from slags by the use of a device comprising at least two cells separated by partitions and connected to each other by means of through-holes provided at the bottom part of the partitions, a slag charging hole, a copper matte charging hole, a slag discharge hole, a copper matte discharge hole, and a heating appliance, said partitions being alternately higher and lower, the height of the through-holes through the higher partitions increasing toward the slag discharge holes. Said method includes reduction, sulphidization, and copper matte rinsing of the slag, the copper matte rinsing of the slag being accomplished by its successive movement from one cell into another through a copper matte layer in alternately downward and upwardly directed streams.