FILTER UNIT

摘要

A filter unit is provided to distribute inhaled air uniformly on the whole filter to recover the filter unit pressed or crumpled due to external power, and to increase a lifespan of a filter. A filter unit(100) comprises a front filter part(30), a rear filter part(40), and a sponge structure(50). The front filter part includes at least one or more filter layer. The rear filter part at least one or more filter layer. A perforated hole(42) is formed on the rear filter part. The sponge structure is made of sponge. The sponge structure is interposed between the front filter part and the rear filter part separated from each other. The sponge structure distributes the inhaled air uniformly. The sponge structure reduces pressure drop of the inhaled air.