Abstract: The invention relates to a surgical instrument, especially for emergency medicine, in particular a so-called coniotomy device with which access to the lung is created for supplying air to the lung in cases in which breathing is hindered in the larynx, which device can be fixated internally and externally and has a short, straight indwelling cannula with a fixative rim at its end and with a trocar, the cutting edge of which is perpendicular to the cricoid cartilage, does not allow any wall contacts within the trachea, causes no injuries to the elastic fibers of the ligamentum conicum and can also be equipped with a small closure sac inserted into the trachea along with the cannula, which can be blown up from outside and which makes it possible to close the trachea in the upwards direction, preventing any escape from the trachea of the breathing air blown into the indwelling cannula.