Contact elements in the contact level of a semiconductor device may be formed on the basis of a selective deposition technique, such as electroless plating, wherein an efficient planarization of the contact level is achieved without subjecting the contact elements to undue mechanical stress. A body frame includes a pair of right and left main pipes extending substantially in the back-and-forth direction of a vehicle with a pair of right and left lower pipes disposed under the main pipes and extending substantially in the back-and-forth direction of the vehicle. The holding bracket is grounded and configured for holding and electrically connecting with the workpiece. Sulfur-enriched permeate fractions are rich in sulfur containing aromatic and nonaromatic hydrocarbons and are further treated with conventional sulfur removal technologies, e.