The device for measuring the specific surface of solid samples contains the body of the device, which consists of a hollow cylindrical container, one base with a bottom and another base which contains an opening for inserting the sample to be measured. A closing head for closing the opening of the device body, the closing head has a seal at least in the part of its surface which contacts the device body. A tube for connecting the body through the closing head of the device to the measuring instrument, the body of the device and the closing head are detachably connected to each other and the seal is a steel O-ring around the circumference of the inner surface of the cylinder head of the sealing head and is covered with a layer of Teflon. The solution also relates to a method of measuring the specific surface of solid samples and using the device to measure the specific surface of solid samples.