Abstract: Means are provided for continuous filtration of foreign matter from a fluid stream, without requiring a discontinuance of filtration to clean filter surfaces. The apparatus alternately directs the fluid to be filtered to one or another of a plurality of filter compartments, each containing a filter medium. Sensing means are provided to sense the condition of filter clogging in the compartments, and diverting means are provided to divert the flow of fluid to a compartment having a relatively clean filter, when a clogging condition is sensed. Thus, the fluid stream is always directed to a filtering compartment having relatively clean filter media therein. Additionally, means are provided for cleaning the filter medium in a compartment not being used.