To maintain the freshness of fish and meat (especially respective slices and chops) and preserve them for a long term by the bacteriostatic treatment of them.

The freshness of fish and meat (especially respective slices and chops) is maintained in such a way as to be able to preserve them for a long term by decreasing volume expansion in icing water in cells of fish or meat and checking natural oxidation of lipid due to cytoclasis through the following steps: most of bacteria adhering to fish and/or meat is excluded by removing through vacuum suction free water floating between/among cells of fish and/or meat preliminarily treated; the propagation of bacteria is restrained by sterilization treatment with hot air in post-processing; and instant freezing is performed by being quickly cooled down to <-5°C.