Patent ID: 8136674

Claim:
A filter device comprising: a filtering member having a rough part, which is low in a density of flow pores for flowing fluid, and a dense part, which is high in the density of the flow pores; and a first support member being in a cylindrical shape that supports the filtering member, and has a discharge passage, a second support member being in a cylindrical shape that supports the filtering member, and has an inflow passage, wherein the dense part supports the rough part, the dense part includes: a bottom portion being in a plate-shape, the bottom portion being located between the rough part and the discharge passage and supporting the rough part; and a side wall portion extending in an axial direction of the first support member from the bottom portion and covering at least a portion of a side surface of the rough part in a radial direction, the dense part is supported by being applied with a mechanical pressure from at least one of the first support member and the second support member, the rough part is in contact with the dense part such that fluid is able to flow through the rough part and the dense part in this order, the bottom portion of the dense part entirely covers a bottom surface of the rough part, and the filtering member further includes an intermediate layer disposed between the rough part and the bottom portion of the dense part.