A package structure includes a substrate, an insulator, a plurality of pads and a patterned circuit layer. The substrate includes a plurality of through holes. The insulator covers the substrate and is filled in the through hole. The conductive vias are located in the through holes and penetrate the insulator filled in the through holes. The pads are disposed on an upper surface and a lower surface of the insulator and electrically connected to the conductive vias. A bottom surface of each pad is lower than the top surface of the insulator. The patterned circuit layer is disposed on the top surface of the insulator and connected to the conductive vias and the pads. A bottom surface of the patterned circuit layer is lower than the top surface of the insulator.