Member states
  1. Twelve founding members

    The CERN convention was signed in 1953 by the 12…

    Know more
  2. Austria joins

    Austria became a Member State of CERN on 1 June…

    Know more
  3. Spain joins

    From the minutes of the CERN council, dated 14…

    Know more
  4. Yugoslavia quits

    On 29 September 1961, the Federal Republic of…

    Know more
  5. Spain quits

    At the request of the Spanish government, Spanish…

    Know more
  6. Spain rejoins

    The return to CERN as a Member State in 1983…

    Know more
  7. Portugal joins

    Portugal joined CERN as a Member State in 1986.…

    Know more
  8. Finland joins

    On 1 January 1991, Finland joined CERN as the…

    Know more
  9. Poland joins

    The first contacts between Poland and CERN were…

    Know more
  10. Hungary joins. So does the Czech and Slovak Federal Republic

    Hungary Hungary joined CERN in 1992, but…

    Know more
  11. The Czech and Slovak Federal Republic ceases to exist

    By a letter dated 16 December 1992, the Permanent…

    Know more
  12. The Czech Republic and the Slovak Republic join

    The Czech Republic joins Statement of the…

    Know more
  13. Bulgaria joins

    Bulgaria became a full member state of CERN on 11…

    Know more
  14. Israel joins

    From CERN press release dated 15 January 2014:…

    Know more
  15. Türkiye joined as CERN’s first Associate Member State

    Türkiye joined as CERN’s first Associate Member…

    Know more
  16. Romania joins

    From CERN press release dated 17 July 2016: On…

    Know more
  17. Serbia joins

    From CERN press release dated 24 March 2019:…

    Know more
  18. Brazil becomes Associate Member State of CERN

    Brazil has become the first Associate Member…

    Know more
  19. Estonia becomes our 24th member state

    The Estonian flag was raised at a ceremony held…

    Know more
  20. Ireland becomes an Associate Member State

    On 8 May 2025, CERN Director-General Fabiola…

    Know more
  21. Chile to become an Associate Member State of CERN

    On 16 May 2025, CERN Director-General Fabiola…

    Know more