Hydrogen is a clean fuel that has diverse applications in the industry, such as applications in energy storage, cooling, fuel cell and car manufacturing. But hydrogen gas is extremely dangerous due to its special properties such as odorless, colorless, non-tasting and highly flammable. Hydrogen is also highly reactive and, by reacting with some gases in the medium such as fluorine and chlorine, is capable of producing harmful acids. Therefore, in order to consider safety points, it is very necessary to detect the presence and concentration of this gas in space. In this regard, in this research, a flexible hydrogen gas sensor was constructed using sputtering of palladium particles on filter paper (filtration membrane) to detect hydrogen gas at room temperature. The manufacturing process is simple and inexpensive, and the sensor can be produced in large dimensions. It should be noted that the use of porous membrane with micrometric fibers and palladium layers in thicknesses above 10 nm in the manufacture of gas sensors for the first time has been investigated. Experimental results indicate that the sensor has sensitivity, reversibility, stability and extraordinary reproducibility, and can be used well at room temperature. The effect of changing the thickness of the palladium layer (which is controlled by the change in sputtering time) as well as the change in the concentration of hydrogen gas in sensor properties was investigated. The effect of bending of the sample on its resistance to hydrogen presence and its absence was also considered. In the end, it was found that increasing the thickness to about 43 nm improves the sensing properties of hydrogen gas compared to lower-thickness specimens. X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermal analysis (TGA / DTA) were performed to analyze and characterize the samples. Hydrogen gas sensor tests were also performed using iviumstatic device.