To provide an instruction system capable of efficiently piling up picked article in a case on a pallet and facilitating conveying work after that.

This instruction system 1 is constructed to give instruction to pick article W in a case unit and to pile the same up on a pallet P. The instruction system 1 is provided with a grouping means 23, a layered-piling instruction means 24, and a stacking instruction means 25. The grouping means 23 groups the article W of the same case shape fractional to be palletized out of a group of the articles W instructed to be shipped. The layered-piling instruction means 24 gives instruction to pile up the article on the pallet P to form an article layer R which is a layer having the article W in the group arranged in a plane. This instruction is, for example, an instruction of items and number of articles W picked per pallet, and information that the articles W of the item and the number form an article layer R. The stacking instruction means 25 instructs to stack pallets with the articles W not reaching a predetermined height.