A ceramic filter is a device made of ceramics, used for some form of filtering or separation process. It may refer to either
Separation
Ceramic water filter, a fine-pored filter used for purifying water
Vacuum ceramic filter, an improved rotary vacuum-drum filter, using a ceramic filtering element to remove water or solvent from slurries so as to extract solids Diesel particulate filter, a ceramic device for cleaning small particles from the exhaust of diesel engines
Electronics
'Filtering' is the process of separating a signal by frequency, see electronic filter Ceramic filter is based on ceramic resonators, which is a piezoelectric ceramic element that has a narrow response to a particular frequency Crystal filter, a similar device, using quartz crystals SAW filter, a ceramic filter using a surface acoustic wave, rather than bulk material effects FBAR or TFBAR filters are based on thin-film bulk acoustic resonators, utilising BAW (bulk acoustic wave) effects and manufactured by thin-film methods