An electrochemical gas sensor measures gaseous components in an air/gas mixture. A measuring electrode and a counterelectrode, with an electrolyte located therebetween, are arranged in the sensor housing. A diffusion barrier is configured to set a gas flow of the gas intended for the concentration determination to the measuring electrode from a surrounding area. The diffusion barrier is located in the sensor housing. At least one gas-permeable, hydrophobic pressure absorption element covers the diffusion barrier and is provided between the diffusion barrier and the measuring electrode, in the interior of the sensor housing and on an inner surface of the sensor housing. The inner surface has a mean roughness depth Rz that is lower than or equal to 2 μm at least in an area on which the pressure absorption element lies.