The aim of this doctoral thesis was the mechanical characterisation of different microstructures of the TiAl alloy TNM-B1 adjusted by means of thermo mechanical processing and subsequent heat treatments. Main focus of interest was directed towards the evaluation of cyclic and static fracture mechanical data as well as creep properties of different microstructures at various temperatures from room temperature up to 800°C. The mechanical characterisation of tensile, fracture and creep properties were tested on different microstructures in dependency of temperature. These results were discussed in reference to their particular microstructural features. In order to adjust the investigated microstructures, investigations on phase diagrams and continuous cooling transformation behaviour were carried out. The occurring microstructural transformations in dependency of testing parameters are described and supported by material-physical models.