Abstract: A plasma filtration device has a plasma module and a filter. The filter is mounted outside of the outlet side of the plasma module. A high-electric field is formed in the plasma module to excite the air to enter a plasma state so that the structures of the hazardous substances are damaged to dissociate into cations and anions. Since the hazardous substances are damaged, the hazardous substances do not harm the users. Further, since the filter is mounted outside of the plasma filtration module, the particles blocked on the filter do not be effected by the electric fields and do not generate the undesired ozone and peculiar smell. Thus, the plasma filtration device achieves high efficiency air clean effect while preventing side effects.