<p>This survey focuses on in-situ studies of solid oxide fuel cells (SOFCs) and other solid oxide electrolyte devices using Raman spectroscopy, which is often combined with other electrochemical and physical methods. Most conventional techniques, for example, structural and microscopy techniques and methods of elemental analysis, cannot provide an opportunity to conduct in-situ analysis of the processes that occur in the materials, electrodes, and entire SOFCs due to high operating temperatures (up to 850–900&#xa0;°C), high current densities (often up to the level of several A/cm²), aggressive gas environments, and separated cathode and anode gas chambers. Conventional electrochemical techniques cannot provide the local information. On the contrary, Raman spectroscopy enables remote, noninvasive, local and molecular-sensitive testing of SOFCs, thus making it possible to obtain information on the macro- and microscopic mechanisms and to perform targeted optimization of the composition, microstructure, and operating conditions of SOFC components. This review aims to cover recent research focused on separate SOFC materials, electrochemical half-cells, and full SOFCs. Special attention is given to carbon deposition at SOFC anodes fueled with hydrocarbon-containing mixtures, mechanisms of hydrocarbon electrooxidation, anode reduction kinetics, poisoning with S- and Cl-containing impurities, variations in oxygen chemical potential, and assessment of emerging mechanical stresses.</p>