PROBLEM TO BE SOLVED: To provide a method for easily freezing cooking "frozen Nigiri-Zushi" or "frozen Oshi-Zushi", which manufactured by combining seafood such as raw sea bream, mackerel and scallop with molded vinegared rice and quickly freezing them, at optimal eating states without cooking the sashimi, and a product.SOLUTION: A mold container with a cover is formed by using a resin as a material. A body of the container has needed number of recesses for including one each molded vinegared rice as rice for Nigiri-Zushi, formed as fractionated partitions, and back of the cover has projections for fitting and holding seafood sashimi which is slice cut with a bite-size formed at positions corresponding to the number of vinegared rice of the body of the container. The molded vinegared rice and the seafood sashimi are input to or fitting hold with the combined container with the cover, quick freezing is conducted on each and top sealing is conducted on the container body and the cover back with a resin film for inhibition of contact of the vinegared rice and the seafood, inhibition of dryness during storage and further inhibition of moisture loss when the vinegared rice is thawed with a microwave. The container body and the cover on which such treatment is conducted are combined and winding sealed with the resin film or the like and then stored in a freezer. During eating, a part of corners of the top seal of the container body is detached as first and vinegared rice inside is heat thawed with microwave at 500 W for 2.5 min. (in the case of 6 sets) at 70 to 90°C. Then the top seal of the cover is detached and the cover is applied so that frozen seafood sashimi is pushed to heated vinegared rice and held for 5 to 10 min. During the term, sashimi is thawed to an optimal temperature by excess heat of the vinegared rice and the vinegared rice is cooled to a temperature suitable for eating at 20 to 25°C. Because weight ratio of the seafood sashimi which is combined as Nigi
