A washing machine includes a casing, a tub, a drum, a circulation pump, an annular gasket connecting between openings of the casing and the tub and including circulation nozzles configured to supply water into the drum, and a conduit fixed to the gasket and guiding water to the circulation nozzles. The conduit includes an inlet port configured to receive water from the pump, a transport pipe configured to guide water from the inlet port to the circulation nozzles, and a supply ports configured to supply water to the circulation nozzles. A method for manufacturing a conduit includes positioning supply ports in a cavity defined at a first mold, forming a parison having a hollow opening by extruding a raw material, positioning the parison in the cavity, combining the first mold and a second mold, and injecting gas into the hollow opening of the parison.