When an explosive in water is exploded, shock wave from the explosive propagates in water as underwater shock wave. Using a detonating fuse as an energetic source, an oblique underwater shock wave with high pressure is obtainable and possible to be utilized for various applications. It is expected that the use of water can inhibit the heating effect on the shock processed sample. In the present research, the authors are intended to use underwater shock wave for the food processing. After loading underwater shock wave against some foods, it is expected to show some advantageous effects for the food processing, such as, softening, improved permeability, and grinding foods. However, such advantageous effects are changed depending upon the condition of the received food. In this research, the foods containing high amount of water were treated by the underwater shock wave. Japanese radish and apple were used as food samples. The change in their hardness, permeability and so on were measured. These results were compared with the control sample in which the underwater shock wave was not applied.