The possibility of application of thin films of phthalocyanines in the design of an optical sensor intended for determination of microquantities of hydrogen sulfide and nitrogen oxide in the atmosphere is considered. It is shown that the use of such films allows to increase sensitivity and selectivity of sensor control. In particular, the use of copper phthalocyanine with a thickness of 50 nanometers allows to reliably determine at room temperature the presence in the air of 100ppb H 2 S and 1ppb NO 2 .
