We have been conducting research on pyrolysis, its manufacturing technology and the use of carbon products with the objective of promoting pyrolysis as a recycling technology. The merits of pyrolysis include 1) reduction of weight and volume, 2) reduction of bad odors, and 3) increase in handling capability, etc. The degree of merit depends on the source materials and process utilized. The main characteristics of the carbon products are 1) lightweight, 2) porous media, 3) black body, 4) alkaline, etc., which are dependent on the source materials and pyrolysis conditions, such as temperature. The carbon products are mainly used for agricultural soil improvement and deodorizing materials, etc. The pyrolysis process creates carbon products and generates power, thus making it possible to achieve sustainable material circulation systems.