Box for accommodating plate body

The purpose of the present invention is to provide a plate-body-accommodating box capable of safely storing, transporting, and shipping, without causing problems such as fracturing, a readily bendable plate body (G) represented by thin to very thin large-size glass substrates. An inner-insertion-side plate (3, 3) having vertical grooves provided to the inside surface side of a pair of side-wall bodies (12X, 12X) facing a main body (1) is placed in a state in which sliding motion and securing are possible by means of inserting and removing operation members (5, 5) in gap-shaped spaces (S, S) provided to both sides of the plate, and the plate body (G) can be switched between a flat posture and a curved posture by means of cooperative action with bottom-edge position-limiting members (4) having horizontal grooves provided to the inner bottom-surface side of a bottom body (11).