We have presented a practical procedure of milling spatial surfaces with 6- axis industrial robot KUKA KR 150 L150 for the production of sail hulls in particular. We used software as SolidWorks, SolidCAM and KUKA.SimPro, KUKA.CAMRob. Polystyrene foam material, also known as "stirodur", was used as stock model. During the milling process, simulation showed the clumsiness of software, since this type of machining is still to be developed. We proved that the robot can mill any kind of spatial surface and assume that by improving the flexibility of the software, the processing of softer metals, composites and wood could increase in future.