PROBLEM TO BE SOLVED: To suppress remarkable deterioration in texture due to the transfer of moisture or a seasoning liquid into a food material when thawing a frozen food in eating, and deterioration in quality caused by that the taste of the seasoning liquid is not given and desirable flavor is not obtained due to the transfer of the seasoning liquid originally adhered to the surface of an ingredient for giving flavor into an ingredient.SOLUTION: An ingredient is cooked with an agar-containing seasoning liquid, and the ingredient and the seasoning liquid are integrated and frozen so as to hardly cause the transition of moisture to the ingredient when thawing and to prevent deterioration of texture and taste.SELECTED DRAWING: None