Disclosed is a polymeric electret film as well as the method of manufacturing the same. The polymeric electret film comprises a polytetrafluoroethylene film and an electrode layer. The polytetrafluoroethylene film includes a porous layer, which has a porous structure. The porous structure has a pore diameter ranging between 0.01 μm and 5.0 μm and has a porosity ranging between 20% and 95%. The polytetrafluoroethylene film has a thickness ranging between 1 μm and 50 μm, and is preferably made of expanded porous polytetrafluoroethylene. The polymeric electret film has a surface potential ranging between 0.1 V and 1000 V.