Abstract: This invention discloses an apparatus and a method for producing activated carbon with high quality from feedstock of bamboo scaffolding waste, waste wooden pallets and the like. The apparatus is an indirect heated rotary kiln comprises a rotary shell; at least one heating tube adapted to be fixedly positioned inside said rotary shell; and at least one activation agent injection pipe adapted to be fixedly positioned within the stationary heating tube. The method is characterized in having part of the fuel gas generated in the carbonization process stored in the indirect rotary kiln before being delivered to a furnace for combustion. The method is further characterized in having the activation agent heated inside the furnace prior to a further heating inside the heating tube. After this further heating, the activation agent is injected into the reactor and activates the char therein.