April, 1971 The National Laboratory for High Energy Physics (KEK) was established.

December, 1974 The booster synchrotron of the KEK-PS was completed, and accelerated protons up to 500 MeV.

March, 1976 The KEK-PS was completed, and the first proton beam was accelerated in the main ring to the designed energy of 8 GeV.

December, 1976 Protons were accelerated up to 11.8 GeV in the main ring of the KEK-PS.

May, 1977 Physics experiments were started using fast extracted beams for bubble chamber and beams from an internal target for counter experiments.

April, 1978 Counter experiments with slow extracted beams from the KEK-PS started.

February, 1990 A new experimental hall for PS experiments was completed, and named North Counter Hall (N-Hall).

April, 1992 a deuteron beam was accelerated by the KEK-PS and successfully used for a physics experiment.

October, 1992 Two large-acceptance superconducting spectrometers were completed at two beam lines in the N-Hall, and physics experiments were started.

April, 1995 alpha beam was accelerated by the KEK-PS and successfully used for a physics experiment.

March, 1999 The K2K experiment has been started, and first KEK neutrino beam event found at Super-Kamiokande.