A honeycomb filter includes a pillar-shaped honeycomb structure having a porous partition wall disposed to surround a plurality of cells and a plugging portion, wherein a thickness of the partition wall is 152 to 305 m, a porosity of the partition wall is 35% to 70%, an average pore diameter of the partition wall is 7 m to 24 m, a porous body constituting the partition wall has a communication pore which opens to the surface of the partition wall and communicates with a pore inside the partition wall, and the communication pore has a narrow part where the diameter is partially narrowed, and in a virtual single pore obtained by virtually dividing the communication pore at the narrow part, an average of a ratio (X/Y) of a minimum width X (m) to a maximum width Y (m) passing through the center of gravity of the virtual single pore is 0.51 to 1.00.

A ceramic membrane filtration assembly comprising a membrane assembly extending from a first membrane assembly end to a second membrane assembly end, where the membrane assembly is defined by a membrane assembly length, the membrane assembly including at least one membrane. At least one of the membranes have channels therein, and at least one channel has channel ends. The filtration assembly further includes at least one sealing device coupled with the membrane assembly adjacent to at least one of the first and second membrane assembly ends, where the sealing device has an inner and outer perimeter. The sealing device has a sealing feature disposed along the outer perimeter, and the inner perimeter of the sealing device is sealed with a portion of the membrane assembly.

In a well array filter (1), a plurality of wells (3) are formed in a filter body (2), the wells (3) adjacent to each other are separated by a well partition wall (6), two or more through-holes (8) are formed in a well bottom portion (4), the minimum width of the opening of the through-hole (8) is 1 m or more and 3.5 m or less, and the ratio of a total opening area of the through-hole is 0.5% or more and 3.5% or less. Assuming a minimum circumscribed circle (G1) that surrounds all of the through-holes (8) in each well bottom portion (4), when the center is moved to the center of each of the plurality of through-holes (8), all minimum circumscribed circles (G2) after movement at least partially overlap all of the plurality of through-holes (8).