A method of manufacturing a substrate using a carrier, that includes preparing a carrier having a releasing layer, and insulating layers and metal layers sequentially disposed on both sides of the releasing layer; patterning the metal layers to form base circuit layers; forming buildup layers on the base circuit layers; executing a routing process to separate the insulating layers from the releasing layer; and forming solder resist layers on the buildup layers and forming openings in the solder resist layers and the insulating layers to expose pads.