Abstract: Apparatus for measuring permeability in rock samples comprising a measuring table (1, 41) for strapping down a rock sample (2), a nozzle (18) that can be pressed against the rock sample (2) at a set force, a gas source (23) connected to the nozzle (18), devices (24) for measuring mass flow through the nozzle and pressure in the nozzle. The apparatus comprises a rack (10,48) equipped with a pneumatic cylinder to which the nozzle is attached and where the rack and measuring table are movable in relation to each other in an X and Y direction via motors. A computer (21) that controls: (a) the motors, and thereby the movements of the nozzle and the measuring table relatively to each other so that the sample is covered by a predetermined measuring point pattern, (b) a mass flow meter (24) that controls and measures the gas flow to the nozzles, (c) a selector valve for compressed air that controls the pneumatic cylinder, and thereby the vertical movement of the nozzle.