There are a large number of invisible micropores in the activated carbon cabin air filter media, most of which are between 5 Å and 500 Å (1 Å = 0.1nm), and the total internal surface area of micropores in the unit weight materials can be as high as 700 m2 / G ~ 2300 m2 / g, that is to say, in a rice sized activated carbon particle, the internal surface area of micropores is equivalent to the inner wall area of a large living room.