The development and the adoption of metadata schemas and standards are a key aspect in data management. In this paper, we introduce our approach to a metadata model in the field of Materials Science. We present the specific use case of a metadata schema for Scanning Electron Microscopy, a characterization technique which is routinely used in Materials Science. This metadata schema is aiming to be a de-facto standard which will be openly available for reuse and further extension to other electron microscopy techniques