Abstract : My research activities are grouped into three main parts from the sensitive layer to the system. The first part focuses on the cold plasma. The plasma environment as physically and chemically very reactive, was mainly used for thin film deposition, but also served as a tool for characterization of surface or gas processing. The second part deals with the development of a gas sensor from the deposition of the sensitive layer to the device. It comes from the assumptions until sensor characteristics. The third part concerns the multisensor systems. In this part, the system consists of several sensors, the feature extraction of the signals and the data processing. Finally, my work in recent issues are quickly exposed in the fourth section of the paper.