Dr. Takashi Okazaki has conducted fusion research, including plasma heating and current drive, blanket, divertor, and safety, and has also been involved in the conceptual design of fusion reactors. In particular, in the field of plasma heating and current drive, he proposed a current drive method with high current drive efficiency. He also proposed the concept of a steady-state operation tokamak reactor, which made a contribution to the steady-state operation of tokamak. With the aim of realizing the experimental reactor, International Tokamak Reactor (INTOR, 1978-1987) was promoted under the initiative of the IAEA, and now International Thermonuclear Experimental Reactor (ITER, 1988-) is being promoted as a subsequent project. He was a member of INTOR Phase Two A Part III.