Ruthenates represent an attractive field of investigation both due to their physical properties (electric conductivity, superconductivity, magnetism – often unconventional) and for their possible technical applications. The heterogeneous in-depth profile of the thin films is extremely important in the fabrication of nanodevices, especially those based on ultra-thin layers. Młynarczyk et al. (pp. 239–254) systematically investigate structural features of epitaxial Sr1 − xCaxRuO3 thin films grown on SrTiO3 and LaAlO3 substrates with the use of high-pressure dc-sputtering. The series of samples were characterized with a number of complementary methods: X-ray diffraction, Rutherford back-scattering, high-resolution transmission electron microscopy, time-of-flight secondary ion mass spectrometry, atomic force microscopy, and X-ray photoemission spectroscopy were used to characterize both in-depth and lateral structure features. Possible applications of Sr1 − xCaxRuO3 thin films are largely determined by their thermal and chemical instability. Excessive process of aging was observed for the samples prepared with high pressure dc-sputtering stored under normal conditions. Progressive stoichiometry instability at the surface layer in a presence of adsorbates should be noted as it significantly limits potential applications of these thin films.