PURPOSE: To make a plan of carrying a number of products with high efficiency by stacking them in multiple layers close to a maximum accessible height.

CONSTITUTION: A delivery information input part 1 inputs information for stacking plural types of products by layer unit for delivery, and a layer stacking type setting part 2 sets a type to be stacked on a pallet in order. A type equivalent laeyr height converting part 3 obtains the relative height rate Bi/Xi of height rate Bi ((i) is an index for identifying the type to be stacked) when an accessible layer height Xi is taken as 1 by the type set by the layer stacking type setting part 2. A layer stacking height computing part 4 integrates the relative height rate Bi/Xi of the respective products which are stacked on a pallet to judge whether or not the rate reaches 1. When the obtained rate has not reached 1, products are stacked onto a pallet, and when the rate has reached 1, stacking is indicated to the other pallets for the products whose rate has exceeded 1. Moreover, a layer stacking command part 5 outputs, to a controller, a command for stacking products in order onto a single pallet or plural pallets according to the command of the layer stacking height computing part 4.