Faced with a proliferation of initiatives like corporate accelerators, entrepreneurial ecosystems see emerge new spaces that we can call entrepreneurial micro-ecosystems. A micro-ecosystem is a local open system interacting with the entrepreneurial ecosystem and driven by an actor or group of actors capable of fostering dynamics of innovation and entrepreneurship. The literature has tended to focus on the macro and meso levels leaving behind the microlevel and the strategies implemented by the actors that could lead to the creation of micro-ecosystems. In this study, we consider corporate accelerators, still little studied, as entrepreneurial micro-ecosystems. We propose to take a structural and strategic approach in order to better understand the attributes and the strategies put in place by these actors from a multilevel approach. A qualitative study was conducted on a corporate accelerator and the results reveal the importance of strategic attributes in terms of legitimacy, coopetition, and business model.