Standard Fan Filter Unit (FFU) is a motorized fan cleanroom equipment with HEPA/ULPA Filter, which can be installed in the filter ceiling grid of a cleanroom.

FFU often consists of a pre-filter, a HEPA/ ULPA filter, and the motorized fan with frame, which pull air through the filters for distribution to cleanrooms or enclosed work stations such as hoods. Large cleanrooms require a large number of FFUs, which in some cases may range from several hundred to several thousand.