Recently, Japan has constructed the largest number of proton and heavy ion therapy facilities in the world. They have produced fruitful results, and now the particle therapy attracts an great attention. The author could fortunately have the opportunity to involve in the research and development of the particle therapy facilities, from the beginning of the entering into National Institute of Radiological Sciences. I started from the investigation of a thermal neutron capture therapy at first, and have been concerned with the development of the facilities for the fast neutron therapy, the proton therapy, and the present heavy ion therapy. Based on these experiences, I would like to review on the history of the particle therapy in Japan and on the latest developments.
