Fe₂O₃ is one of the most important metal oxides for gas sensing applications because of its low cost and high stability. It is well-known that the shape, size, and phase of Fe₂O₃ have a significant influence on its sensing properties. Many reports are available in the literature on the use of Fe₂O₃-based sensors for detecting gases, such as NO₂, NH₃, H₂S, H₂, and CO. In this paper, we investigated the gas-sensing performance of a Pt-doped ε-phase Fe₂O₃ gas sensor. Pt-doped Fe₂O₃ nanoparticles were synthesized by a Sol-Gel method. Platinum, known as a catalytic material, was used for improving gas-sensing performance in this research. The gas-response measurement at 300℃ showed that Fe₂O₃ gas sensors doped with 3%Pt are selective for NO₂ gas and exhibita maximum response of 21.23%. The gas-sensing properties proved that Fe₂O₃ could be used as a gas sensor for nitrogen dioxide.