Leaving the microwave open while it's not in use should not directly damage the food inside it. However, there are a few considerations to keep in mind:
Exposure to air: When the microwave door is left open, the food inside may be exposed to ambient air, which can lead to moisture loss or drying out of the food. This can affect the texture and quality of certain foods, especially if they are prone to drying out quickly.
Contamination: Leaving the microwave open can expose the food to airborne particles, dust, or other contaminants in the environment. While this may not cause immediate damage, it can affect the cleanliness and safety of the food.
Heat loss: When the microwave door is open, the heat generated by the microwave will dissipate into the room rather than being contained inside the microwave cavity. If you're in the process of heating or cooking food and leave the door open, it will take longer for the food to reach the desired temperature.
To maintain the quality and safety of the food, it's generally recommended to keep the microwave door closed when not in use. This helps preserve moisture, prevent contamination, and maintain the efficiency of the microwave's heating capabilities.