Wind power, which is one of the promising renewable energies, has shown the high growth rate of 35 % of the annual average in the recent 5 years and also windmill related equipment market has been fast-growing. Yaw & Pitch bearing are the key parts of windmill and are machined by huge vertical lathe which is monopolized by the advanced countries. The purpose of this study is to develop the multi-tasking vertical lathe for 5 MW grade windmill bearings, which might be mass produced 3 or 5 years later. In this study, the structure of the crossrail and rotary table, which are the key units of the huge multi-tasking vertical lathe, were optimized through the finite element analysis. Also the basic performance of the rotary table has been evaluated.