A filtering apparatus includes a filter with meshes having a periphery enclosed by a metal frame, an antibacterial material layer formed on the filter, a negative ions generator stretching into the filter for generating negative oxygen ions, and an electrode plate disposed on the metal frame. The metal frame is affected by the electrode plate to produce a high voltage electric field, thereby activating the antibacterial material layer under a piezoelectric effect to release more negative oxygen ions and silver ions. The negative oxygen ions and the silver ions collide together within the filter and become finer, thereby absorbing smelly odor passing through the filter to the maximum extent, purifying air, destroying germs, and promoting the air quality of the environment.
