Sensors for determining humidity in air have been described and investigated. Sensing film of the devices was prepared from polyvinylalcohol and graphitized carbon black disperse phase. The composition, thermal treatment and design of sensing films were investigated and optimized. An optimized humidity sensor has better metrological parameters as compared with its prototype (response time approximately 45 s, detection limit 0.17%, slope 6.25 +/- 0.05 Theta/R.H., standard deviation of measurement 0.15%, standard deviation of analytical signal in the graduation equation 8.29Theta). Such construction of sensors have prospects in analytical practice.