Material processing technology utilizing a new method for generating a neutral radical beam is proposed. The method, named photo-deionization of negative ion beam (PDINIB), can be expected to generate a refined beam of neutral radicals (RBNR), that is to say, an ultra-pure beam of a desired neutral radical species whose momentum spectrum consists of a very narrow peak around a desired value controllable over a wide range. In this paper, the principle and the procedure of the PDINIB method are described along with fundamental design of the RBNR apparatus in the author's laboratory. Then, expected advantages of the PDINIB method are discussed in comparison with conventional methods. Furthermore, a technique to generate RBNR of chemical species characterized by negative electron affinity, a typical example of which is atomic nitrogen, is proposed as an application of the PDINIB method.