Abstract: The vortex flow sensor is designed to measure the mass flow rate, the volumetric flow rate, or the flow velocity of a fluid flowing in a flow tube having a tube wall, and has two temperature sensors arranged in such a way that the vortex flow sensor may also be used with fluids which would corrode the temperature sensors. A bluff body in the flow tube sheds vortices and thus causes pressure fluctuations. A vortex sensor device responsive thereto is fitted downstream of the bluff body in a hole provided in the wall of the flow tube. The vortex sensor device comprises a sensor vane extending into the fluid. The temperature sensors are disposed in a blind hole of the sensor vane. Alternatively, the temperature sensor may be disposed in blind hole of the bluff body.