Stainless steel bowls can't be heated by microwave. Metal can only reflect microwave, but can't penetrate and absorb it. If the stainless steel lunch box is put into the microwave oven, the food inside can't be heated. Metal utensils should not be used in microwave heating, because the utensils such as iron, aluminum, stainless steel and enamel put into the furnace will generate electric sparks and reflect microwaves when heated, which will not only damage the furnace body but also heat the uncooked food.

Do not use metal utensils for microwave heating: Because the utensils such as iron, aluminum, stainless steel and enamel put into the furnace will generate electric sparks and reflect microwaves when the microwave oven is heated, which will not only damage the furnace body but also heat the uncooked food. Avoid using closed containers: wide-mouth containers should be used when heating liquids, because the heat generated by food heating in closed containers is not easy to dissipate, which makes the pressure in the containers too high and easily leads to blasting accidents. When cooking food with a shell, it is also necessary to pierce the shell with a needle or chopsticks in advance, so as to avoid bursting after heating, splashing to pollute the furnace wall, or splashing to hurt people.