A gas routing element (20) for gassing at least one gas-measuring device (90.1-90.x), whereby each gas-measuring device (90.x-90.x) can be arranged in a test module (30.1-30.x) of a calibrating station (100). The gas-measuring devices (90.1-90.x) have a first gas inlet opening (1.1-1.x), a communicating feed duct (2.1-2.x) and a communicating first gas outlet openings (3.1-3.x, 13.1-13.x). Second gas inlet openings (4.1-4.x, 14.1-14.x) are connected to a communicating recirculating duct (5.1-5.x) and a second gas outlet opening (6.1-6.x) is connected with the recirculating duct (5.1-5.x) in a gas-communicating manner. A fastening device (70) fastens the gas routing element (20) to the calibrating station (100) or to a test module (30.1-30.x) of the calibrating station (100). A calibrating station (100) is also provided for the gas-measuring devices (90.1-90.x) with such a gas routing element (20).