A method for fabricating a packaging substrate includes: providing a carrier having a first metal layer and a second metal layer formed on the first metal layer; forming a first circuit layer on the second metal layer and forming a separating portion on an edge of the second metal layer such that the separating portion is spaced from the first circuit layer; forming a dielectric layer on the second metal layer and the first circuit layer such that the first circuit layer and the separating portion are embedded in the dielectric layer and portions of the dielectric layer are formed between the first circuit layer and the separating portion; forming a second circuit layer on the dielectric layer; and applying forces on the separating portion so as to remove the first metal layer and the carrier, thereby maintaining the integrity of the first circuit layer.