FILTER ELEMENT

PROBLEM TO BE SOLVED: To provide a filter element which is manufacturable with reasonable costs and available in a variety of filtration applications and is used in cross-flow filtration and dead end filtration.SOLUTION: A filter element 12 includes a porous sheet material 40 and an unfiltered liquid supply apparatus. The porous sheet material includes an unfiltered liquid side and a filtered liquid side and is arranged in a plurality of pleats 42 extending in the longitudinal direction. Each pleat has first and second wall parts 46 and 47 extending, perpendicularly to the longitudinal direction, from a first opened end to a second closed end, with the first wall part and the second wall part separated mutually. The unfiltered liquid supply apparatus extends in the longitudinal direction of the pleats and fluid-communicating practically with a first end part or a second end part of each pleat along the entire length of the pleat. In a liquid supply apparatus, an opening designed in such a way as to give a fluid flow in a direction nearly perpendicular to the longitudinal direction of the pleats from the liquid supply apparatus into the pleats is provided.