A new indirect method of estimating in situ soil air permeability is presented in this technical report. The new method is simply based on the measurement of air pressure (probe pressure) generated by pumping a constant air flux inside a special designed probe inserted into the soil. To calibrate the method, some measurements of the probe pressure were performed in some soils of the island of Vulcano, characterized by different values of the air permeability. Furthermore, technical aspects of a new device for performing continuous acquisition of the air permeability based on the new indirect method, were also described