The field of application of ceramic and ceramic composite layers has expanded from sensitive biomedical applications to the area of aggressive industrial environments. Plasma spraying as one of the thermal spraying processes is very popular among the various coating processes. However, layers that are produced with this method are not free of defects and require post-treatment in order to obtain the desired layer properties. In this paper, both the original layers and the layers processed with the microwave polishing process are monitored in two different test environments. Investigations of the physical (porosity), mechanical (hardness and adhesive tensile strength), and functional (wear resistance) properties are carried out. It turned out that these evaluation techniques can be used to evaluate the quality of the layers. The experimental procedure for the tests is briefly presented. The results are discussed using illustrations. Paper includes a German-language abstract.