Patent ID: 8596775

Claim:
A filter unit comprising: a space portion, through which a liquid passes, whose outer cross-sectional shape when cut along a direction orthogonal to an axial direction is circular or polygonal; a filter provided at a surface on one end side of the space portion in the axial direction thereof; a protruding member, provided at a surface on the other end side of the space portion in the axial direction thereof, that protrudes toward a center area of the surface on the one end side of the space portion; an inflow channel that allows the liquid to flow into the space portion from a direction tangential to a side circumferential surface of the space portion; and an outflow channel that allows the liquid to pass through the filter and flow out from the space portion, wherein the protruding member has a circular conical shape whose apex points toward the one end side of the space portion in the axial direction such that the apex is over the center area above a portion where the outflow channel leaves the space portion.