Chemical Vapor Deposition (CVD) is employed in this study to create MWCNT thin films. The examination of X-ray diffraction (XRD) shows that there are several strong peaks at 2θ ~ 35.5°, 54°, 57°and 62° which are attributed to the ( 222), ( 004), ( 104) and (015) planes, respectively. This leads to the conclusion that the sample is polycrystalline in nature with a hexagonal crystalline structure. The Field Emission Scanning Electron Microscope (FE-SEM) images highlight the shape of CNTs produced on catalyst particles using the CVD process. MWCNTs are synthesized in a variety of forms, including straight arrangement, branching arrangement, coil MWCNT structures, curly and helical-shaped structures. A reduced sensor is conceivable; this could result in a sensor that is lighter, cheaper and consumes less power. A MWCNT thin film is fabricated as a gas sensor based on glass substrates, where CH4 and CO2 gases with concentrations of 1, 2, 3 and 4 ppm are examined, and this study is conducted to see how the absorption of CH4 and CO2 gases affects the change in the resistance of CNT pellets. According to the study, CNTs are highly sensitive to gases like CH4 and CO2. Future research into CNT-based sensors is expected to focus on a wide range of applications as the interest of the nanotechnology research community in this area grows.