to the base face 7 the base face 7 is configured as a flat plate an extension 8 is formed on the base face 7 in this exemplary embodiment the plane of the extension 8 extends orthogonally to the plane of the base face 7 the third oscillation node plate 6 is connected u2014 on the inlet side and the outlet side u2014 to the housing structure 5 of the coriolis mass flow meter 1 by the extension 8 the web which is foamed by the extension 8 is arranged at an angle to the plane of the base face 7 and is braced on a face of the housing structure 5 with a force fit the extension 8 is configured so that it passes through the plane of the base face 7 and is fastened on the base face 7 the third oscillation node plate 6 therefore extends in two planes so that an advantageous flexural stiffness is achieved the extension 8 is configured to be wider in the upper region u2014 see fig1 i e in the region of the base face 7 than in the lower region u2014 see fig1 where the extension 8 is braced on the housing structure 5 the plane of the extension 8 extends centrally in the base face 7 between the two measurement tubes 2 parallel to the mid axes of the two measurement tubes an advantageous flexural stiffness of the third oscillation node plate 6 is achieved by this configuration besides the measuring equipment electronics 9 e g sensor.