PURPOSE: To enhance the perfectness of a casting by removably mounting a nozzle and filter assembly which includes a nozzle for supplying molten metal from a launder to a casting mold and has a filter for filtering the molten metal flowing through the nozzle at the launder.

CONSTITUTION: This launder system 16 is used to supply the molten metal from a source for the molten metal 14 to the casting mold or secondary stage. The system includes the nozzle 22 arranged to supply the molten metal from the launder to the casting mold or the secondary stage and has the filter 26 arranging within the nozzle in order to filter the molten metal flowing through the nozzle. The assembly of the nozzle and the filter is removably mounted at the launder. As a result, the launder system which allows the use of the launder ≥2 times in order to build the filter by taking the advantage of ceramic linings may be obtd.