A package substrate includes a core board having a through hole; a circuit layer formed on the core board; a metallic ring disposed on the core board surrounding a contour of the through hole, the metallic ring having opening portions positioned opposite to each other, making the metallic ring having a disconnected manner; and an embedded component installed in the through hole. When the embedded component is deviated in the through hole to allow the electrodes to be in contact with the metallic ring, the electrodes are prevented from coming into contact with the same section of the metallic ring to thereby avoid short circuit.