A grating apparatus grates an object to be grated, and includes an upper mill including an upper mill grinding surface and an opening portion in a center of the upper mill grinding surface, a lower mill located below the upper mill and including a lower mill grinding surface abutting on the upper mill grinding surface, and a core at least partially located in the opening portion. The core includes a plate-shaped portion which rotates, and an engagement portion engaged with an object to be grated is provided in a peripheral end surface of the plate-shaped portion.