Kenji Kazato and Kazuo Ito met while working at the Naval Central Institute in Tokyo during World War II.

[10][11] This initial group developed a prototype magnetic field–type electron microscope called the DA-1, which was sold to Mitsubishi in 1947.

[10] The Japan Electron Optics Laboratory Company, Limited (Nihon Denshi Kogaku Kenkyujo)[13] was founded in 1949 by Kenji Kazato and Kazuo Ito in Mitaka, Tokyo.

[12] Kazuo Ito has expressed the company's philosophy as follows: "On the basis of creativity, and research and development, JEOL (日本電子) positively challenges the world’s highest technology thus forever contributing to the progress in both science and human society through its products.

[15] Kenji Kazato retired as president of JEOL in 1975, but continued to act as an adviser to the company until his death in 2012.

Finally, the Medical Equipment segment manufactures automatic analysis devices, clinical diagnostic systems and amino acid analyzers.

[citation needed] The company's direct analysis in real time (DART) mass spectrometry system has appeared on the television program CSI: NY.