Patent ID: 7449110

Claim:
A filter which has at least two filter elements having a substrate comprising a cylindrical porous body having many pores and having a plurality of cells as flow paths for untreated liquid and a filtering membrane comprising a porous body smaller in average pore diameter than that of the substrate and formed on the inner wall of a plurality of the cells, and said at least two filter elements are contained in a casing, wherein said at least two filter elements contained in the casing are connected in series in such a state as interposing a first sealer between them, and the first sealer separates liquid-tightly a plurality of the cells from a space formed between the outer peripheral surface of said at least two filter elements and the inner peripheral surface of the casing and does not hinder a plurality of the cells of said at least two filter elements from communicating with each other, wherein the first sealer is a seal cap.