The invention discloses a mask capable of effectively filtering PM2.5 and a manufacturing method of a PET hole film. According to the purpose that the PM2.5 mask can filter inhalable particles in the atmosphere, the manufactured PET hole film is mainly improved in the aspects of irradiation ions, ultraviolet irradiation power, wavelength and time. The manufactured mask used for filtering the PM2.5 can intercept particle with diameter smaller than or equal to 2.5 micrometers out of the filtering film of the mask, and using efficiency of the mask is high.