The High Energy Accelerator Research Organization (高エネルギー加速器研究機構, Kō Enerugī Kasokuki Kenkyū Kikō), known as KEK, is a Japanese organization whose purpose is to operate the largest particle physics laboratory in Japan, situated in Tsukuba, Ibaraki prefecture.

Makoto Kobayashi, emeritus professor at KEK, is known globally for his work on CP-violation, and was awarded the 2008 Nobel Prize in Physics.

As such, KEK was not the only new institute created at that time, because not all of the work of the parent institutions fell under the umbrella of high energy physics; for example, the Center for Nuclear Study, the University of Tokyo, was concurrently established for low energy nuclear physics in a research partnership with RIKEN.

The theoretical operation performance of SR16000, a super computer made by Hitachi, is 46 TFLOPS.

The theoretical operation performance of Blue Gene Solution, a super computer made by IBM, is 57.3 TFLOPS.