A sensor for detecting the mass flow rate and the temperature of a fluid flow has a mass flow rate sensor having a mass flow rate sensor element, a temperature sensor having a temperature sensor element, and an interface for power supply. The sensor converts the measured values detected in analog by the mass flow rate sensor element and the temperature sensor element into digital output signals. In order to specify the simplest and most economical sensor possible for detecting the mass flow rate and the temperature of a fluid flow, at least one analog/digital converter is arranged in the sensor, which analog/digital converter converts the analog measured values of the mass flow rate sensor element and/or the analog measured value of the temperature sensor element into digital output signals and provides the digital output signals at a single digital interface.