Synergic effect of the individual components of the indoor environment is considered to be a significant determinant of the quality of the indoor environment. The quality of the indoor environment affects not only the user's comfort but also the health of the users of the buildings. The main objective of the paper is to confirm or exclude a statistically significant impact of hygro-thermal conditions on the indoor air quality (IAQ). Hygrothermal conditions and indoor air quality are the essential components of the indoor environment. The indoor air temperature [°C], the relative humidity [%] and the indoor air quality are monitored in the apartment of the prefabricated residential building (Ostrava, Czech Republic) during several months. The measuring MEMS MOS gas sensor AS-MLV-P2 contains a metal oxide semiconductor based gas sensor detecting differences the concentration of harmful substances such as alcohols, aldehydes, ketones, organic acids, amines, and aliphatic and aromatic hydrocarbons. The measured gas concentration is calculated with an algorithm into a CO(2) equivalent [ppm]. The observed values are subjected to correlation analysis.