This paper presents an approach to the importance of gas sensors at industry, at the health sector and at home. Throughout history it has been necessary to detect gases, at first we used the nose, the gas sensor that we have incorporated in our body but later it was inevitable to develop sensors to replace the olfactory system to avoid risks and increase detection efficiency. Examples of application in each of the mentioned sectors are presented and the importance of each of them is analyzed. Science and technology development have allowed advances in the production of sensors that are used in the monitoring of toxic gases, explosion safety systems, as environmental detectors, smoke detection systems in our homes and recently in SARS-CoV-2 virus detection strategies and risk reduction of contagion during the COVID-19 pandemic through biomarker sensors and monitoring of CO2 concentrations, respectively. It is shown how gas sensors have helped our society in its purpose of ensuring a better life quality for those of%