The purpose of this thesis was to study what are the material requirements for wind power units. It was also studied how external influences, such as weather conditions, alter these requirements. In addition to ordinary weather conditions, it was studied what kind of particles and other impurities are in the air, and how the-se might affect a wind power unit. The main focus of this thesis was to study the different materials used in the con-struction of wind power units and the requirements each main section (tower, na-celle and blades) have for the materials used. It was also studied how these re-quirements changed when the unit was constructed in or near a body of water. In addition to the above, the materials commonly used at the time to writing were studied in this thesis. A small part of this thesis is given to the study of next gener-ation materials. The material for this study was searched from libraries and from databases in the internet. The study revealed that the use of old materials, such as steel, is very common. Also, different kinds of composite materials are commonly used.