A device for detecting a gas or gas mixture has a first and a second gas sensor. The first gas sensor is a MOSFET, which comprises a first source, a first drain, a first channel zone disposed between the latter elements, and a first gas sensitive layer capacitively coupled to the first channel zone that contains palladium and reacts to a change in the concentration of the gas to be detected with a change in its work function. The second gas sensor has, in a semiconductor substrate, a second source, a second drain, and a second channel zone between the latter elements, which is capacitively coupled via an air gap to a suspended gate. The latter comprises a second gas sensitive layer that reacts to a change in the concentration of the gas to be detected with a change in its work function. The second gas sensitive layer is arranged on a support layer and faces the air gap. The support layer is formed by another semiconductor substrate, and the first gas sensor is integrated in the front side of the second semiconductor substrate facing away from the air gap.