The contribution provides a concise overview of ion beam analysis methods and pro- cedures in studies of materials exposed to fusion plasmas in controlled fusion devices with magnetic confinement. An impact of erosion-deposition processes on the morphology of wall materials is- presented. In particular, results for deuterium analyses are discussed. Underlying physics, ad- vantages and limitations of methods are addressed. The role of wall diagnostics in studies of mate- rial migration and fuel retention is explained. A brief note on research and handling of radioactive and beryllium-contaminated materials is also given.