Detecting air ingredients is obtained, a heater and gas sensitive acting layers are arranged on a substrate, which are connectable to an analyzing unit. Electrical resistances of n acting layers are connected in series; heater is a temperature sensor connected in parallel with this series connection, electrical resistance of heater is smaller than the sum of electrical resistances of acting layers and resistances are connected with a total of n+1 electrical terminals via electrodes so that heater is connected with two terminals and n−1 other terminals are connected with a respective junction that interconnects two acting layers. Heater is intermittently heated so that a predefined constant temperature of acting layers is achieved, temperature of acting layers is acquired by determining electrical resistance of heater; voltages in the series connection of acting layers are analyzed and a concentration of gases are determined from electrical resistances of acting layers.