A high temperature filter and a self-cleaning filtering system for filtering media, such as biomass materials, are provided. The filter and filtering system is particularly useful in the filtration of syngas in a plasma arc gasification process to remove char and other particles of down to a submicron size from the syngas. The filter is formed from a pleated metal mesh material including end caps secured by a high-temperature metallic paste or adhesive, such that the filter is capable of withstanding operating temperatures up to 2000° F. The system includes a backflush unit for injecting cleaning media therein to remove trapped char and other debris from the filter. At least two filtering systems can be placed in parallel so that one system can be cleaned while the other is operating. A method for filtering media is also disclosed.