A manufacturing method of an interposed substrate is provided. A metal-stacked layer comprising a first metal layer, an etching stop layer and a second metal layer is formed. A patterned conductor layer is formed on the first metal layer, wherein the patterned conductor layer exposes a portion of the first metal layer. A plurality of conductive pillars is formed on the patterned conductor layer, wherein the conductive pillars are separated from each other and stacked on a portion of the patterned conductor layer. An insulating material layer is formed on the metal-stacked layer, wherein the insulating material layer covers the portion of the first metal layer and encapsulates the conductive pillars and the other portion of the patterned conductor layer. The metal-stacked layer is removed to expose a lower surface opposite to an upper surface of the insulating material layer and a bottom surface of the patterned conductor layer.