No, plastic lunch boxes can be heated in the microwave oven, but only those marked with microwave can be put in the microwave oven. Plastic lunch boxes can withstand the high temperature of 200 degrees and can be heated by microwave oven. Other ordinary plastic lunch boxes, such as take-out boxes and pc lunch boxes, are not heated by microwave ovens. It should be noted that ordinary plastic containers, metal containers, porcelain with metal edges and closed containers should not be used in microwave ovens. Ordinary plastic containers are easy to deform when heated by microwave oven, releasing toxic substances, polluting food and endangering human health. When metal utensils are heated in the microwave oven, it will produce electric sparks to reflect microwaves, which is easy to cause fire hazards. When a microwave oven heats a closed container, the inside of the container is heated to produce pressure, which is easy to explode if the pressure is too high. Microwave heating tableware: 1. Glass lunch boxes include borosilicate glass, glass ceramics and titanium oxide crystal glass. Glass is suitable for long-term use in microwave ovens because of its good penetrability, stable physical and chemical properties and high temperature resistance. A glass, bottle, etc made of ordinary glass. It is only suitable for microwave heating for a short time, about 3 minutes. If the heating time is too long, it will break easily. 2. Ceramic lunch box ceramics are divided into heat-resistant ceramics and ordinary ceramics. Lunch boxes made of heat-resistant ceramics are suitable for long-term use in microwave ovens, while ordinary ceramic lunch boxes can only be heated for a short time.