To provide a packing material that forms, in a simple method, a cargo unit of predetermined height or above by arranging many cartons in a stack.

The packing material 10 disposed at each corner of a pallet 1 and used for arranging many cartons 2 in a stack includes: an L-shaped angle 11 formed by bending a plate-like member at right angles into an L shape and disposed at the corner of the pallet 1; and projecting support parts 12 and 13 extending inside the L-shaped angle 11 from the lower end of the L-shaped angle to a predetermined height. The cartons 2 are stacked on the pallet 1 such that the cartons 2 arranged above the upper ends of the support parts 12 and 13 out of the cartons 2 to be stacked are displaced in the outward directions of the pallet 2 from the cartons 2 arranged below the upper ends of the support parts 12 and 13. The support parts 12 and 13 support the ends of the cartons 2 arranged so as to be displaced in the outward directions.