A new process to prepare activated coke from organic wastes such as mixtures of waste wood and waste plastics has been investigated. The process consists of pre-carbonization of organic wastes, a wet-briquette forming of the pre-carbonized product and carbonization of the briquette to produce activated coke. The activated coke prepared was found to have a sufficientry high mechanical strength and relative surface area for applycation as an absorbents in a moving bed type gas purification plant (i.e., purification plant for exhaust gas from sintering machine). The gas evolved in the pre-carbonization was also found to have a high caloric value and can be used for a heat source for the process. This study examined the effects of process variables such as carbonization temperature, time and the raw materials on the yield and on the properties of activated coke. In the pre-carbonization of mixtures of waste wood and waste plastics at weight ratios from 100/0 to 60/40, the yield of coke was found to remain constant. To explain this phenomenon, a co-carbonization mechanism of cracking materials from waste plastics on the surface of carbonized waste wood was proposed.