On the basis of such relationships, it can be said that, even if the volume of air is increased to accelerate the rise of fruit temperature, it only adds to the pressure with relatively little effect on the fruit temperature. Performance of differential pressure treatment also varies with factors such as the size of fruits due to the species and the height of stacking fruit containers, etc. There is an optimal condition for the treatment of each different fruits. It is, therefore, necessary that the most suitable treatment condition for each kind of fruits should be sought after by repeating experiments.