The Solar cooker works. on the same principle as

A solar cooker works on the principle of the greenhouse effect. The glass cover sheet placed on top of the solar cooker allows short-wavelength infrared and visible solar radiation to pass through into the inner black box. Once absorbed, this energy is re-radiated as long-wavelength infrared radiation, which cannot pass back out through the glass plate. This traps heat inside the enclosure, steadily raising the temperature to cook food.