A method of manufacturing a coil inductor and a coil inductor are provided. A plurality of conductive bottom structures are formed to be lying on a first dielectric layer. A plurality pairs of conductive side structures are then formed, wherein each pair of the conductive side structure stand on top surface of a first end and a second end of each conductive bottom structure respectively; a second dielectric layer is formed on the first dielectric layer, coating the bottom and side structures; and a plurality of conductive top structures are formed to be lying on the second dielectric layer, wherein each conductive top structure electrically connects each pair of the conductive side structures, wherein the conductive bottom structures, the conductive side structures and the conductive top structures together form a conductive coil structure.