Bag filter media were prepared by a combination of needle punching and thermal bonding processes and treated with Polytetrafluoroethylene(PTFE) aqueous solution. The air permeability of the prepared filter media increased with increasing needle strokes. As needling strokes increased, the pore size distribution became narrow and the tensile strength in the machine and cross direction approached an intermediate value suggesting isotropic nature. From the result of air filter performance test, the pressure difference of bag filter media decreased and the collection efficiency increased with increasing-needle strokes under a constant air flow rate. Both air permeability and average pore size of the coated filter media were largely reduced by the PTFE coating treatment. After PTFE coating, we identified a big decrease in the dust concentration compared with control media. Therefore, the filtration performances such as collection efficiency and pressure difference of bag filter media were promoted by the PTFE coating treatment.