A wafer boat according to the present disclosure includes a plurality of support columns, each having a pillar shape and comprising a plurality of grooves configured to have a wafer placed thereon, and support plates configured to support both end portions of the plurality of support columns, respectively. Each of the plurality of support columns are formed of a ceramic containing aluminum oxide or silicon carbide as a main constituent, and an outer side surface of the plurality of support columns is a ground surface and/or a polished surface.

Disclosed is a graphite disc solving a problem of poor performance uniformity of the epitaxial wafer, which is obtained during material epitaxial growth by using the graphite disc. The graphite disc includes a graphite disc body, where the graphite disc body includes a groove and a plurality of projections on a bottom wall of the groove, and the plurality of projections divide the groove into a plurality of independent regions. According to the graphite disc provided by the present disclosure, a plurality of regions are defined in the groove by using the projections, each region corresponds to one substrate, and different regions are interconnected. Compared with the graphite disc structure with one groove corresponding to one substrate in the related art, a space for gas flow is enlarged, therefore a problem that an edge of the epitaxial wafer is too thick caused by gas flow is alleviated.