Abstract: An air-permeable member of the present disclosure includes a porous ceramic having a columnar or plate shape. A root mean square slope R?q in a roughness curve of an outer peripheral surface of the porous ceramic is greater than a root mean square slope R?q in a roughness curve of a main surface of the porous ceramic.

Abstract: A member for a plasma processing device of the present disclosure is a member for a plasma processing device made of ceramics and having a shape of a cylindrical body with a through hole in an axial direction. The ceramics is mainly composed of aluminum oxide, and has a plurality of crystal grains and a grain boundary phase that is present between the crystal grains. An inner peripheral surface of the cylindrical body has an arithmetic average roughness Ra of 1 ?m or more and 3 ?m or less, and an arithmetic height Rmax of 30 ?m or more and 130 ?m or less.

Abstract: A porous ceramic of the present disclosure contains yttrium zirconate and yttrium oxide, and at least one of them is a main component. A member for a semiconductor manufacturing apparatus such as a shower plate, a plug or the like in a semiconductor manufacturing apparatus is made of the above porous ceramic.

Abstract: A shower plate according to the present disclosure includes a ceramic sintered body, the ceramic sintered body comprising a first surface, a second surface facing the first surface, and a through hole positioned between the first surface and the second surface. An inner surface of the through hole includes a protruding crystal grain which protrudes more than an exposed part of a grain boundary phase existing between crystal grains. In addition, a semiconductor manufacturing apparatus according to the present disclosure includes the shower plate mentioned above.

Abstract: A member for a plasma processing device of the present disclosure is a member for a plasma processing device made of ceramics and having a shape of a cylindrical body with a through hole in an axial direction. The ceramics is mainly composed of aluminum oxide, and has a plurality of crystal grains and a grain boundary phase that is present between the crystal grains. An inner peripheral surface of the cylindrical body has an arithmetic average roughness Ra of 1 ?m or more and 3 ?m or less, and an arithmetic height Rmax of 30 ?m or more and 130 ?m or less.

Abstract: A shower plate according to the present disclosure includes a ceramic sintered body, the ceramic sintered body comprising a first surface, a second surface facing the first surface, and a through hole positioned between the first surface and the second surface. An inner surface of the through hole includes a protruding crystal grain which protrudes more than an exposed part of a grain boundary phase existing between crystal grains. In addition, a semiconductor manufacturing apparatus according to the present disclosure includes the shower plate mentioned above.