A wiring structure and a method for manufacturing the same are provided. The wiring structure includes a conductive structure and a plurality of conductive through vias. The conductive structure includes a dielectric layer, a circuit layer in contact with the dielectric layer, a plurality of dam portions and an outer metal layer. The dam portions extend through the dielectric layer. The dam portion defines a through hole. The outer metal layer is disposed adjacent to a top surface of the dielectric layer and extends into the through hole of the dam portion. The conductive through vias are disposed in the through holes of the dam portions and electrically connecting the circuit layer.