The process of firedamps´ release into worked-out areas, which often communicate with the surface after stopping the coal mining activity is very topical problem in the region of Ostrava. Firedamps contain namely dangerous methane, which is a result of the coalification process. Contemporary findings in this area show that the outflow of firedamps into the atmosphere is above all related to barometer pressure´s development. In 1995, the realization of degassing wells was initiated in region of Slezská Ostrava. Within the fremawork of monitoring, methane concentrations, gas-air mixture amount and barometer rates are measured among others. This paper gives information about mathematic data processing originated from the monitoring unit of the degassing well used for leading of firedamps from the underground, which is situated in Slezská Ostrava region