Abstract: An environmental load equation storage section that stores the environmental load equations modeled on a stage at which a product is produced and used and a stage of waste treatment and recycling, with the life cycle of the product being divided into at least the two stages, a unit load emission storage section that stores conversion coefficients used to convert the amounts of materials and energy consumed in producing, using, waste-treating, and recycling the product into the amount of environmental load factors emitted as a result of those operations, an input section for entering the amounts of materials and energy consumed in producing, using, waste-treating, and recycling the product, for each of the modeled stages, a computing section that calculates the amount of emission of environmental load factors by applying the amounts of materials and energy fed and the conversion coefficients corresponding to the amounts to the environmental load equations, an assessment section for assessing a load that the pr