To provide a bookrack plate and a bookrack that are usable books of various sizes.

This bookrack plate 10, having a plate-shaped mounting block 11 for placing a book 1 thereon and a receiving part 12 provided to project from the lower end edge of the mounting block 11 for receiving the book 1, includes a page holder 13 extended in the vertical direction of the mounting block 11 and being slidable in the horizontal direction of the mounting block 11 to hold the open pages of the book 1. Since the page holder 13 is adapted to be slidable in the horizontal direction of the mounting block 11, the bookrack plate 10 can be adapted to books 1 of various sizes by moving the page holder 13 along the horizontal direction of the mounting block 11.