One direct outcome of the project will be a coherent textbook on optical nanospectroscopy. The research results and networking activities will be made accessible via a public website. This Action will advance current knowledge on processes such as energy flow and light-matter-interaction at the nanoscale and lead to innovations in interdisciplinary areas across (bio-)physics, chemistry, biology, nano-/materials science, and engineering. Knowledge about the preparation and properties of novel samples, in particular hybrid combinations of components, will be gained. Novel specifically designed supramolecular structures and nanostructuring techniques will result from the Action and have a wider impact. The limits of the spatial and temporal resolution that can be achieved with nanospectroscopy will be pushed further. Potentially new levels will be reached in the advancement of devices such as photovoltaic cells, LEDs, biosensors, or spasers. Nanospectroscopy techniques will be further developed with respect to performance and user-friendliness. By addressing technology-transfer issues, COST NanoSpectroscopy is expected to impact the dissemination of nanospectroscopy techniques beyond the research laboratory and make them more accessible to general users. As a facilitator for advances in fields like energy efficiency, materials science, light harvesting, optoelectronics, and medicine, its long-term societal impact promises to be considerable.