Sensors play a crucial role in various sectors, including information technology, medicine, industry, and environmental monitoring. Among these, semiconductor sensors made from polymeric films, such as polyaniline (PAni), are particularly valued for their functionality at room temperature. This study focuses on developing a poly(methyl methacrylate) (PMMA)/PAni membrane using a notably low concentration of PAni, which demonstrated a remarkable variation in sensor sensitivity, achieving a difference of four orders of magnitude. The sensitivity of chemical gas sensors is significantly influenced by their specific surface area; therefore, we employed electrospinning—a cost‐effective technique that produces fibers with micro‐ to nanometric diameters, thereby significantly enhancing surface area. Our aim was to improve the electrospinning parameters configuration to create PMMA/PAni membranes with uniform fibers for gas detection applications. We evaluated three PAni concentrations (2.5 wt.%, 5 wt.%, and 7.5 wt.%) to understand their effects on the membrane's microstructure and gas response. Characterization techniques, including scanning electron microscopy, thermogravimetric analysis, and electrical conductivity measurements, revealed that a 2.5 wt.% PMMA solution produced the best fiber formation. Notably, the PMMA membrane containing 5 wt.% PAni exhibited reduced electrical resistance upon gas exposure, highlighting its strong potential for sensor applications.