24 countries are a part of the organization: the member states of the European Union and the associated members provided by the organizations (alphabetically a source):
Austria: JKU - Johannes Kepler University of Linz
Болгария: NCSA - Executive agency "Electronic communication networks and information systems"
Кипр: CaSToRC – Computation-based Science and Technology Research Center, The Cyprus Institute
Czech republic: V Š B - Technical University of Ostrava
Дания: DCSC - Danish Center for Scientific Computing
Finland: CSC - IT Center for Science Ltd.
Франция: GENCI - Grand Equipement National de Calcul Intensif
Germany: GCS - GAUSS Centre for Supercomputing e.V
Греция: GRNET - Greek Research and Technology Network S.A.
Венгрия: NIIFI - National Information Infrastructure Development Institute
Ireland: ICHEC - Irish Centre for High-End Computing
Israel: IUCC - Inter-University Computation Center
Italy: CINECA - Consorzio Interuniversitario
Норвегия: SIGMA – UNINETT Sigma AS – The Norwegian Metacenter for Computational Science
Нидерланды: NCF – Stichting Nationale Computerfaciliteiten – Netherlands Computing Facilities Foundation
Польша: PSNC – Instytut Chemii Bioorganicznej Pan – Institute of Bioorganic Chemistry – Poznan Supercomputing and Networking Center
Portugal: FCTUC – Faculdade Ciencias e Tecnologia da Universidade de Coimbra
Serbia: IPB - Institute of Physics Belgrade
Словения: ULFME - University of Ljubljana, Faculty of Mechanical Engineering
Испания: BSC – Barcelona Supercomputing Center – Centro Nacional de Supercomputación
Швеция: SNIC – Vetenskapsrådet – Swedish Research Council
Швейцария: ETH – Eidgenössische Technische Hochschule Zürich – Swiss Federal Institute of Technology, Zürich
Турция: UYBHM – Ulusal Yuksek Basarimli Hesaplama Merkezi, Istanbul Technical University – National Center for High Performance Computing
Great Britain: EPSRC – The Engineering and Physical Sciences Research Council