The project aims to develop a reusable face mask filter using nanofiber technique to relieve the social and environmental burden caused by current one-time using face masks. The filter consists of electrospun nanofibers with much smaller diameters (e.g., nm level), which are much smaller than the commercial filter fibers (e.g., µm level). The developed nanofibrous filter has high air filtration efficiency without sacrificing the breathe comfortability, which can be attributed to its high porosity and improved physical structure. The filter design is also highly flexible to incorporated with other physicochemical methods for further improvement of the filter properties. An impressive feature of this invention is the reusability. Simple chemical washing can regenerate the exhausted filter for further reuse with maintained high air filtration performance.