TRIPLE FOLD FILTER BAG

A triple foldable filter bag is provided to treat a large amount of liquid phase contaminants by increasing surface area of a nonwoven fabric layer of a filter, reduce the replacement cost by extending service life of the filter bag, and obtain convenience during replacement of the filter bag by attaching a handle to the filter bag. A triple foldable filter bag comprises: a triple foldable filter member(10) in which a large diameter part(11), an intermediate diameter part(12) and a small diameter part(13) are formed succeedingly, which are superposed on one another to expose the large diameter part only, which has an opening(11a) formed in one side of the large diameter part, and which is made of nonwoven fabric; and a shape-maintaining member(20) interposed between the intermediate diameter part and the small diameter part during superposition of the triple foldable filter member to maintain the triple foldable filter member in the form of a pipe, wherein during the superposition of the triple foldable filter member, the shape-maintaining member is inserted onto the small diameter part in a state that the triple foldable filter member is unfolded, and the shape-maintaining member is interposed between the intermediate diameter part and the small diameter part by pushing the small diameter part onto which the shape-maintaining member has been inserted to an inner side of the large diameter part. The large diameter part has a handle(11b) formed on an upper end of an inner peripheral surface of the opening.