Abstract: A structure of a heater for a packing machine which can be mounted on a packing machine such as a food container to thermally seal a wrapping paper such as a film includes: a heating part for generating heat if electric power is applied to the heating part and thermally fusing the wrapping paper to the food container in a hollow closed curve shape; and a connecting part connecting the heating part to a power source, and wherein an upper or lower surface of the heating part contacts the wrapping paper to heat the wrapping paper so that the wrapping paper is thermally fused to the food container.