A substrate structure is provided, which includes: a substrate body having a plurality of conductive pads; an insulating layer formed on the substrate body and exposing the conductive pads; a plurality of conductive vias formed in the insulating layer and electrically connected to the conductive pads; a plurality of circuits formed on the conductive vias and in the insulating layer, wherein the circuits are greater in width than the conductive vias; and a plurality of conductive posts formed on the circuits and the insulating layer, wherein each of the conductive posts has a width greater than or equal to that of each of the circuits. The conductive vias, the circuits and the conductive posts are integrally formed. As such, micro-chips or fine-pitch conductive pads can be electrically connected to the substrate structure in a flip-chip manner.