air purifier; air filter
Refers to a device that removes dust, pollen, odors, or other particles from the air, commonly used in homes and offices.
An air purifier is indispensable during hay fever season.
This air purifier makes it easy to replace the filter.
More common synonym for 'air purifier'; 空気浄化機 is a less frequent variant with the same meaning.
Compound of 空気 (air) + 浄化 (purification) + 機 (machine). The exact derivation is straightforward; the word is a modern technical term.