There is described a mass flow meter which operates on the Coriolis principle. A measuring tube is mounted in a chamber, which is provided with at least two openings for directing the medium to and from the respective end of the measuring tube. The mounting of the measuring tube is arranged between the two tube ends at an axial distance from them. It is preferably at an oscillation node of the first bending mode. The mounting arranged at an axial distance from the tube ends has the advantage that thermal expansions have virtually no influence on the internal mechanical stress conditions of the measuring tube, and consequently scarcely influence the measurement result. The mass flow meter can be used with particular advantage for gaseous media.