Abstract: Injection device and procedure for using the device for introducing air and/or additive to the deeper layers of soil The subject of the invention is an injection device and procedure for using the device for introducing air and/or additive to the deeper layers of soil, which device is suitable for introducing air and/or additive to the deep layers of soil with high pressure, where the arrangement of the device makes sure that air and/or additive is spread to a large area, and it also ensures that the air and/or additive cannot flow back to the surface along the device. Furthermore, with the help of the procedure while using the device it is possible to introduce proper quantity of air and/or additive into the deeper layers of the soil corresponding to the given soil quality. Injection device consisting of base body having longitudinal hole, and one end of the base body is formed with tapered tip, and there are holes in the lower and upper parts of the base body, which are connected to the longitudinal hole.