Glass has a transparent window in the wavelength range 0.3 to 3 μm and it is not transparent to the
radiation which has wavelength range greater than 3 μm . Therefore, because the microwaves are in the
range of 102 to 105 μm , the harmful microwave radiation cannot escape from the glass door.
We can see the inside of a microwave oven during operation through is glass door,which indicates that visible radiation is escaping the oven. Do you think that the harmful microwave radiation might also be eseaping?