Abstract: An air-mass sensor having an air mass sensor module provided with two temperature sensors (6, 7) and two heat sensors (4, 5) which are incorporated into two separately acting bridges (I, II) whose bridge output signals (Umv, Umh, Umq) are supplied to a microprocessor (16) incorporated on a common support with the air-mass sensor module. The microprocessor (16) is calibrated such that crude bridge signals (Usv, Ush, Usq) measured in a base mode are inscribed in support places (x1, x2, x3) of support place tables (St2, St3). A customer characteristic curve is filed in the form of measurement points (m1, m2, m3) in the support place tables (St2, St3) and are utilized to adjust the crude bridge signals.