To easily trace even processed food through a complicated production process.

Each food agent A, B, etc. transmits delivery data wherein a product ID and a raw material ID are associated, about a product delivered to the other food agent A, B, etc. that is a direct delivery opposite party. The delivery data are distributively stored in agent PCs 20, 20, etc, possessed by the respective food agents A, B, etc. When a management PC 30 performs tracing, only the delivery data having relevance are collected by the management PC 30 on the basis of the product ID and the raw material ID, and a distribution route can be specified by jointing them. Accordingly, it is not necessary to produce history data penetrating processes overstriding the plurality of food agents in each product even when the distribution route is complicated, and it is not necessary to always manage vast data together with the product.