Abstract: A method of making a semiconductor device having formed thereon an inductor comprises a silicon substrate. A cut out region is obtained by removing a part of the silicon substrate in a hollow shape which may be a hollow cavity or a hollow cavity with an insulating material having a low complex permittivity such as silicon oxide buried therein. An insulator layer is formed on the cut out region and on the periphery thereof. A connection layer serves as one of the leads of the inductor and is formed using an electric conductive material such as a metal or doped polycrystalline silicon. A contact hole is provided in the interlayer insulation layer. A connection layer serves as an inductor and the other lead of the inductor, which is formed using an electric conductive material such as a metal. A protective insulator layer is also provided on the top of the structure.