Abstarct: The sensing carbon dioxide gas is very important issue for the human health and his life environmental and industrial applications. But in the sensing of carbon dioxide and other gases such as methane it happens some challenges. Diagnostic of some gases such as Methane and carbon dioxide (CO_2) by using of resistance sensors is so hard because of its weak signal that is about a few millivolt (0.05 volt) because of electronic noice interference, this is if the element voltage is about 5 volt. Even though by using of Amplifier this voltage could reach to 100 millivolt but the signal (CO_2 signal) vanished by the system noises. For this reason the resistance gas sensor for carbon dioxide diagnosing aren’t precise sensors. But on the other hand for CO_2 diagnosing could use of absorption spectrum light sensor that have strong absorption lines. In relation with studying and structuring this sensor you will face with two basic challenges. Challenge one: since the proper absorption lines for CO_2 molecule is in the Infrared range, there for providing of its emitter and photo detector is hard. Challenge two: sensor elements fee is somewhat high. For that CO_2 sensors with low charge expanded in the industrial fields, it decided that by using of material nanostructure and nanostructured material reduced CO_2 gas sensor limits. In the other words we somehow cause to increase sensitivity that sensor signal overcome from system noises. No dispersed Infrared gas sensor for detecting carbon dioxide (CO_2) gas had studied in two general fields: 1. Designing of light emitter electronic circuit and infrared photodiode detector, with other related elements. 2. Studying of theory of interaction between carbon dioxide gas and Infrared light. In continuation, studying and structuring of resistance gas sensor in basis of semiconductors oxide ZnO and SnO_2 considered. Sensing of carbon dioxide gas with two different types of thin films SnO2 and ZnO with 1.5 percent gas density in 300 centigrade degree is done. For providing active martial of sensing element, Nano particles of SnO2 and also ZnO had synthesized by sputtering method. Nano particle surface Morphology is studied with Field Emission Scanning Electron Microscopy (FESEM). Finally, three parameter of sensitivity, respond time and recovery time of Infrared gas sensor with any two type of mextal oxide resistance gas sensor (SnO_2 and ZnO) is compered.