Direct methanol fuel cells (DMFCs) are a promising power source for mobile devices. However, DMFCs currently experience the technical shortcomings of high cost due to the use of noble metal catalysts and polymer electrolyte membranes (PEMs), low power density because of their low catalytic efficiency and cathode catalyst poisoning by methanol, which crosses through the PEM from anode to cathode. Here, we report a new DMFC structure utilizing a polymer fiber membrane (PFM), which is electrolyte-permeable, instead of a PEM. An inexpensive perovskite-type oxide, LaNiO3, is used as the cathode catalyst, which has shown excellent tolerance to methanol-poisoning and good catalytic activity for oxygen reduction reaction (ORR). The peak power density can reach 103 mW cm−2 at 65 °C. This improvement in performance is due to the lower electrical resistance of the PFM.