A process for continuously manufacturing a phosphorized copper alloy wire while adding to molten copper phosphorus and an element less soluble therein than phosphorus. In the process, the less soluble element is added to molten copper fed from a melting furnace in a heating furnace for maintaining the molten copper at a given high temperature. The molten copper fed from the heating furnace is transferred to a tundish. In the tundish, the temperature of the molten copper is dropped, and phosphorus is added thereto. Thereafter, the molten copper from the tundish is fed to a belt wheel continuous foundry machine, and a cast copper material led from the belt wheel continuous foundry machine is rolled to thereby attain the continuous manufacturing of a phosphorized copper alloy wire.