Solid oxide electrolyzers (SOE) are the most efficient yet not fully mature devices for electrochemical production of hydrogen. These devices offer a great advantage in applications which make it possible to utilize process heat or steam to feed SOE for direct conversion of steam instead of water. However, the technology is prone to a degradation, as it combines advanced materials, requires dedicated fabrication techniques and it operates at elevated temperature, typically above 650ºC. One of the biggest challenges is the mitigation of degradation of solid oxide electrolyzers due to the delamination of the electrode. Several measures can be proposed to limit the process, however full elimination of this type of degradation is not yet possible. The good understanding of the mechanisms and consecutive steps which lead to deterioration of the interface between the electrolyte and air electrode of SOE is based on thorough experimental studies supported by the numerical modeling.In the study we present a delamination model, which can be used to identify the safe operating envelope of SOEs with a given structure and material composition. The mechanisms behind degradation through delamination are discussed with respect to the chemical and electrochemical potentials. This is complement by the discussion of criteria for the formation and propagation of cracks, taking into account the oxygen potential at the electrolyte-electrode interface. Moreover, the microstructural modifications of the electrodes, e.g. increase of its porosity, are discussed as one of the potential measures to substantially reduce the risk of delamination under design point and off-design operation of SOEs. The methodology of manipulating the porosity of the electrode by varying the content and type of pore forming agents was proposed in order to adjust the parameters of electrodes to the required microstructure. Results of the experimental characterization of cells fabricated in such a way are presented, and the guidelines for fine-tuning the microstructure are discussed with respect to the degradation mechanisms.