The problems of the meas rin control’s acc racy improvin of the concentration methane optical-absorption analyzer are considered. The scale-model of the high-speed optical methane concentration measuring has been developed and investigated. It is established, that the sensitivity of the output voltage is about 0.51 V/vol.%, the absolute additive error of the methane concentration measurement is 0,02±vol.%, that is much smaller than the absolute error of the methane concentration measurement (up to 0,2±vol.%) in the range from 0 to 4.0 vol.%. The way of the thermal drift compensation of the gas concentration measuring has developed and implemented, where LED is used as thermosensitive element. The hardware implementation of the developed method has allowed to evaluate its effectiveness: the value of the additional error due to the methane concentration measurement changing in temperature is not more than 0,1± vol. %, which is 4 times less than it is required.