To improve the strength and the adsorptive performance by mixing fine coke dust with a specified moisture with coal dust obtained by adding a specified amount of coal heavy oil with a specific viscosity to the coal dust with a specified grain size, at a specified mixing ratio, when molding a mixed coal of a double layer structure with a specified average diameter to be pressed into a raw material with a specified diameter and further, activating the raw material through carbonization at a high temperature.

Several different types of coal 1 are crushed using a crusher 3 and the crushed coals are loaded into a coking furnace 4 and further, are carbonized upto such a state that no gas is generated. After that, the carbonized coals are loaded into a dry cooling tower 5 and then are quenched to recover underwater a fine coke duct with a grain diameter of 200 μm and classified to set its impregnation moisture to 10-20% in a moisture impregnating tank 6. In addition, several different types of coal duct crushed to the grain diameter of 50 μm or less using the crusher 3 are mixed so that the fluidity is 2-3. Further, a coal heavy oil 2 with a viscosity of 50 cp or less at 80°C is added to the coal dust at an addition rate of 10-30% for the weight of carbon, and this mixture is introduced into a kneader 7. The fine coke dust and the coal dust are kneaded by a kneader 8 at a mixing ratio of (8:2)-(6:4) to obtain the molded mixed coal of a double structure with an average diameter of 0.5-2 mm which comprises a coal sticking to a coke surface layer. Further, this molding is formed into a column with a diameter of 10-20 mm under pressure using a molding machine 9 and is activated through carbonization at a high temperature at a heading furnace 10.