PROBLEM TO BE SOLVED: To provide an inorganic filter having a controlled filter channel opening size. SOLUTION: A first flat surface and a second flat surface parallel to each other, and an array of flare-shaped passages extending between the first flat surface and the second flat surface and connected to the first flat surface and the second flat surface. A ceramic filter having a structure including: The plurality of openings in the flared passages are circular, with greater than 90% of the openings having a diameter greater than 0.1 μm. [Selection diagram] Figure 1a【課題】制御されたフィルタチャネル開口サイズを有する無機フィルタの提供。【解決手段】互いに平行な第１平坦面及び第２平坦面と、第１平坦面及び第２平坦面間に延びかつ第１平坦面及び第２平坦面に接続する一配列のフレア状通路とを含む構造を有する、セラミックフィルタ。前記フレア状通路の複数の開口は円形であり、開口の９０％を超えるものが０．１μｍを超える直径を有する。【選択図】図１ａ
