Patent ID: 7407578

Claim:
A liquid filtering instrument for filtering a liquid under pressure-reduced filtration, the liquid filtering instrument comprising: a filter member receiving a filter for a liquid, a holder member that stocks a filtered liquid passing through the filter for a liquid, and a single seal member in a fitting portion between the filter member and the holder member wherein the seal member is a porous membrane filter; wherein said filter member and said holder member are separated by a partition wall that permits fluid communication there between, said partition wall having a step portion which projects into said filter member, and wherein said porous membrane filter is interposed at the fitting portion between the inner side wall of said filter member and the outer peripheral surface of said step portion so that a cross-section of said porous membrane filter is U-shaped; and wherein the filter member and the holder member are capable of being fitted so as to be substantially air-tight and water-tight when a pressure is reduced.