In 1988, the late Prof. Rikimaru Hayashi had first proposed "Use of High Pressure in Food", introducing his views, i.e., "heat and pressure are independently capable of transforming the state of a substance, and such state transforming factors are only heat and pressure in nature." Sc. D. Masaru Nakahara stated in his note that he had been impressed by the unique starting point of Prof. Hayashi's idea. Prof. Hayashi had explored some good method for food processing without using heat, so he alternatively thought of high-pressure treatment (Hayashi R (1989) Use of high pressure to food processing and preservation. In: Hayashi R (ed) Use of high pressure in food. San-Ei Publishing Co, Kyoto, pp 1-30; Nakahara M (1990) Water and ions at high pressure: their fundamental properties relevant to the pressure treatment to food. In: Hayashi R (ed) Pressure-processed food--research and development. San-Ei Publishing Co, Kyoto, pp 3-21). Since the start-up of Japanese research group of high pressure in biological field (the present "Japanese Research Group of High Pressure Bioscience and Biotechnology (JHPBB)") and "International Association of High Pressure Bioscience and Biotechnology (IAHPBB)", we have continued to research into the industrial use of high-pressure treatment over a period of 25 years to realize our dream, that is, the same as Prof. Hayashi's dream. Although heat and pressure were found to be independent factors capable of transforming the state of a substance, use of heat has been overwhelmingly more frequent in food processing up to now. However, the pressure treatment has the advantages of instantaneous transmission, uniform distribution in vessels, and ability of inducing uniform change in quality. The high-pressure treatment does not cause cleavage of the covalent bond in the substance, thereby lessening the decomposition of nutrients, the generation of offensive smell, and the production of abnormal materials when compared with the heat application. In addition, energy consumption in the high-pressure treatment is less than that in the heat treatment. For the reasons mentioned above, the high-pressure treatment has thus been regarded as suitable for future food processing, and much attention has been paid to the researches of high-pressure treatment again. Then, we reviewed the previous researches in which little interest had been taken because of imperfectness of non-heat sterilization. Surprisingly, we discovered some novel findings about the effect of high-pressure treatment, that is, pressure history on the subsequent event. Then, we decided to present two theses on the themes, "Application of High-pressure Treatment to Enhancement of Functional Components in Agricultural Products" and "Application of High-pressure Treatment to Development of Sterilized Foods".