SMT-components known in the art usually have a thickness of approximately 1 mm and no flexibility. According to the present invention windings for an inductor are realized within a substrate, preferably by using copper layers which are already in the substrate. Then, thin metal sheet layers of high permeable material are laminated on top and bottom of the substrate. These layers are structured and then form the magnetic core of the inductor. Advantageously, an inductor may be provided with a very small building height.