1954 Formation of a working group for the foundation of an institute for nuclear study.
1955 The Institute of Nuclear Study (INS) was established.
1957 Sep FF cyclotron was completed.
1958 May
FM cyclotron was completed.
The first experiment with the FF cyclotron took place.
1960 Oct The first experiment with the FM cyclotron took place.
1961 Dec The Electron Synchrotron (ES) accelerated an electron beam to 750 MeV.
1963 Apr The first experiment with the ES took place.
1964 Apr Formation of a working group for the foundation of a new research institute for elementary particle physics.
1966 Mar The ES produced a 1.3 GeV beam.
1971 Apr National Laboratory for High Energy Physics (KEK) was established.
1976 Mar The proton synchrotron (PS) produced an 8 GeV beam as designed.
Dec The PS achieved 12 GeV.
1977 May The first PS experiment took place.
Dec Experiments with the SF cyclotron began.
1978 The Meson Science Facility was established. The Booster Synchrotron Utilization Facility and a Photon Factory (PF) were founded.
1980 Jul Experiments in the Booster Synchrotron Utilization Facility began.
1982 Mar The PF succeeded in storing a 2.5 GeV electron beam.
1983 Jun PF Experiments began.
1984 Jul The TRISTAN Accumulation Ring (AR) accelerated an electron beam to 6.5 GeV.
1985 Oct The AR accelerated a positron beam to 5 GeV.
1986 Nov The TRISTAN Main Ring (MR) accelerated both electron and positron beams to 25.5 GeV.
1987 May TRISTAN experiments began.
1988 The Meson Science Facility was reorganized as a Laboratory (MSL) Nov The MR energy was upgraded to 30 GeV with the help of superconducting accelerating cavities.
1989 Sep First electron cooling by TARNII Accelerator and Synchrotron Radiation Science departments were established in the Graduate University for Advanced Studies
1993 Mar Isotope Separator On-Line (ISOL) was completed.
1994 Jun KEKB B-factory construction began.
1995 Dec TRISTAN experiments finished.
1997 The High Energy Accelerator Research Organization was established.
1998 First beam storage at KEKB (KEK B-factory) ring
1999 Apr The Department of Particle and Nuclear Science was founded in the Graduate University for Advanced Studies.
May The Long-baseline Neutrino Oscillation experiment (K2K) began.
Jun The Belle experiment at the KEK B-factory began operation.
2000 Tanashi Branch closed
2001 Construction of High Intensity Proton Accelerators (J-PARC) started
2004 Apr

Became the Inter-University Research Institute Corporation High Energy Accelerator Research Organization.
K2K experiment ended
2005 Apr
Tokai Campus was opened.
Experiments at PS ended.
2006 Feb
J-PARC Center was established.
Experiments at BSF ended.
2007 Jan
181MeV proton beam at J-PARC Linac
3 Gev proton beam at J-PARC Rapid Cycling Synchrotron (RCS)
2008 Oct Prof. Makoto Kobayashi, former director of IPNS, won the 2008 Nobel Prize in Physics.
2009 Mar J-PARC construction was completed.
2010 Jun The Belle experiment ended
2011 Construction of the SuperKEKB started
2016 Phase 1 operation of the SuperKEKB started