Vortex flow sensor for the measurement of the mass flow, volume flow or flow velocity of a fluid which flows in a flow direction in a measuring tube of the vortex flow sensor, said measuring tube having a tube wall, wherein said vortex flow sensor comprises: - a bluff body arranged along a diameter of the measuring tube, said bluff body -- serving to generate Karman vortices and -- being connected from the inside to the tube wall of the measuring tube at a first and a second fixing point (41, 41') which are located opposite one another, - a vortex sensor responding to pressure fluctuations generated by the vortices, said sensor being inserted downstream from the bluff body in a bore of the tube wall of the measuring tube and sealing said bore, - wherein the center of the bore is located, together with the center of the first fixing point of the bluff body, on a generating line of the measuring tube, and - wherein the vortex sensor comprises: -- a membrane covering the bore with a first surface facing towards the fluid and a second surface facing away from the fluid, -- a sensor tongue secured to the first surface of the membrane, said tongue --- being shorter than the diameter of the measuring tube and --- having main surfaces that are aligned with the generating line, and at least one front edge and --- having a blind hole, the base of which is located near the at least one front edge, -- a temperature sensor, which is located at the base of the blind hole or close to the base, and -- a sensor element secured to the second surface. - a bluff body arranged along a diameter of the measuring tube, said bluff body -- serving to generate Karman vortices and -- being connected from the inside to the tube wall of the measuring tube at a first and a second fixing point (41, 41') which are located opposite one another, -- serving to generate Karman vortices and -- being connected from the inside to the tube wall of the measuring tube at a first and a second fixing point (41, 41') which are located opposite one another, - a vortex sensor responding to pressure fluctuations generated by the vortices, said sensor being inserted downstream from the bluff body in a bore of the tube wall of the measuring tube and sealing said bore, - wherein the center of the bore is located, together with the center of the first fixing point of the bluff body, on a generating line of the measuring tube, and - wherein the vortex sensor comprises: -- a membrane covering the bore with a first surface facing towards the fluid and a second surface facing away from the fluid, -- a sensor tongue secured to the first surface of the membrane, said tongue --- being shorter than the diameter of the measuring tube and --- having main surfaces that are aligned with the generating line, and at least one front edge and --- having a blind hole, the base of which is located near the at least one front edge, -- a temperature sensor, which is located at the base of the blind hole or close to the base, and -- a sensor element secured to the second surface. -- a membrane covering the bore with a first surface facing towards the fluid and a second surface facing away from the fluid, -- a sensor tongue secured to the first surface of the membrane, said tongue --- being shorter than the diameter of the measuring tube and --- having main surfaces that are aligned with the generating line, and at least one front edge and --- having a blind hole, the base of which is located near the at least one front edge, --- being shorter than the diameter of the measuring tube and --- having main surfaces that are aligned with the generating line, and at least one front edge and --- having a blind hole, the base of which is located near the at least one front edge, -- a temperature sensor, which is located at the base of the blind hole or close to the base, and -- a sensor element secured to the second surface.