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.