This project keeps the research data of our study on Demonstration Environments Ontology. Demonstration Environments (DE) refer to all facilities and environments for technology development including testing, prototyping and confronting technology with different usage situations (e.g. testbed, pilot plant, living lab, sandbox, etc.). This DE Ontology is proposed to define, conceptualise and characterise DEs from various perspectives including their application domains, characteristics, network components and measurable values like lifespan. It enables different types of DEs to be situated on the same level for comparison and benchmarking. It also provides a standardisation of terminologies related to DEs which solves heterogeneity in the description of various names of DEs across domains, and provides a common understanding of DEs through a systematic framework which is the ontology. This ontology can be visualised in WebVOWL via https://service.tib.eu/webvowl/#opts=doc=4;#iri=http://purl.org/deo. If you would like to suggest any changes to this ontology, please submit a pull request via GitHub https://github.com/bbkk0502/Demonstration-Environments-Ontology-Version1.0.