In this study, the electrical conduction and bipolar switching properties in transparent manganese oxide thin films were investigated and discussed. The as-deposited manganese oxide thin films were prepared by the rf magnetron sputtering method with the rf power of 130 W, chamber pressure of 10 mTorr, substrate temperature of 550 °C, and different oxygen concentrations. To discuss the resistive switching properties of the manganese oxide thin films, the conventional thermal annealing treatment of the manganese oxide thin film resistive random access memory (RRAM) devices were investigated. Finally, the current-voltage characteristics were determined by the ohmic contact and the Poole-Frankel emission conduction method in low/high-voltage regions, respectively.