Abstract: A process for thawing a frozen sushi product of a type packed by a plastic film by a microwave oven is provided. Each of a packed frozen sushi product of a type packed by a plastic film in which the entire sushi product is covered with the plastic film, and a frozen sushi product of a type packed by a plastic film in which an upper portion of a sushi material is covered with an aluminum foil, and the entire sushi product is covered with a plastic film with the aluminum foil located therebetween, can be thawed in a microwave oven by heating it by an electromagnetic wave heating to rise the temperature of an exposed side of a shaped form of boiled rice to 40.degree. C. or more, while rising the temperature of a contact area between the sushi material and the boiled rice portion to 15.degree. C.