Filter

A filter comprising:

• a filter base portion having a first main surface and a second main surface opposite to the first main surface, the filter base portion defining a plurality of through-holes connecting the first main surface and the second main surface via an inner wall extending from the second main surface toward the first main surface;
• and
• a support portion that has a plurality of protruding portions located in respective through-holes of the plurality of through-holes and disposed on the second main surface of the filter base portion, the plurality of protruding portions having an outer wall in contact with the inner wall of the filter base portion,
• wherein, in the respective through-holes in which the plurality of protruding portions are located, a first opening on the first main surface side of the filter base portion is larger than a second opening on the second main surface side of the filter base portion, and there is a clearance between the filter base portion and the support portion, and
• wherein the support portion includes a plurality of first support members extending in a first direction and a plurality of second support members extending in a second direction intersecting the first direction.