A country can be either a member or an observer of the legal entity ECCSEL ERIC (European Research Infrastructure Consortium). Rights and obligations in ECCSEL ERIC depend on whether a country is a member or an observer. The main difference is that members can attend and vote at the General Assembly, while observers can attend but have no voting rights. The rights and obligations of members and Observers are stated in the ECCSEL ERIC statutes.

Member States of the European Union, associated countries, countries other than associated countries and intergovernmental organisations may become members or observers. An additional requirement for membership is that members must contribute to the operation of ECCSEL ERIC by establishing a country node and bring at least one facility into the ECCSEL ERIC Research Infrastructure.