A semiconductor device includes a semiconductor chip covered with a resin layer, the semiconductor chip including an electrode pad at a surface of the semiconductor chip, a first insulating layer covering the surface of the semiconductor chip and having a via hole at a region corresponding to the electrode pad, a conductive layer extending along a surface of the electrode pad, a side surface of the via hole, and a planar surface the first insulating layer, to a region beyond a planar region defined by the semiconductor chip, a second insulating layer on the first insulating layer and covering the conductive layer; and a molecular bonding layer formed between the first insulating layer and the second insulating layer and including a molecular portion covalently bonded to a material of the conductive layer and a material of the second insulating layer.