<p>A filter separation device in which a piping system structure for piping placed in a drum type filter is simplified to make the structure of the device simple. In an arrangement structure for a raw water supply pipe (32) and a captured matter discharge pipe (36) arranged in a drum type filter (26), the captured matter discharge pipe (36) is inserted and placed in the raw water supply pipe (32), and a hopper (34) of the captured matter discharge pipe (36) is placed at an opening (32A) formed in the upper surface of the raw water supply pipe (32). Because the piping structure of the raw water supply pipe (32) and the captured matter discharge pipe (36) is a double pipe structure using the raw water supply pipe (32) as an outer pipe and the captured matter discharge pipe (36) as an inner pipe, the number of piping systems can be reduced from conventional two systems to one system.</p>
