In this thesis the mechanical and the thermal shock behaviour of complex rod-shaped specimens made of an electroceramic composit-material is characterized. The fracture strength of the composit-material is determined with a one-point-bending test, the three-point-bending test and the four-point-bending test in order to measure different effective volumes and different areas of the specimen. These tests are also used to measure the retained strength of the material after the water quench test. By the size effect it is tried to predict the fracture strength measured by one-point-bending test out of the three-point-bending test and four-point-bending test. The critical temperature difference of the material is determined with a water quench test. In order to describe the thermal shock behaviour it is important to work out all required material properties. The cracks resulting from the thermal shock become visible with the dye-penetration-method. The retained fracture strength of the composit-material is determined with a one-point-bending test, the three-point-bending test and the four-point-bending. The FE-modelling is based on the hypotheses of the linear elastic theory. The computation implies the strongly temperature dependent properties of the composite-material. It will be shown that the value of the critical temperature difference determined with the computation corresponds with the experimental received value.