TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Properties: The air permeability of the activated carbon support, along the thickness direction, is more than 200 cm3/cm2-seconds. The toluene adsorption property of the activated carbon support is more than 40 g/m2, preferably more than 30 g/m2. The specific surface area as determined by Brunauer Emmett Teller (BET) method, is 1200-2500 m2/g, preferably 900-2000 m2/g.    TECHNOLOGY FOCUS - POLYMERS - Preferred Polymer: The fibrous polymer used as the raw material of a fibrous activated carbon knitted fabric has size 150 dtex or more. EXAMPLE - Phenol type fiber having a single fiber size of 2.2 dtex and a filament-like size of 295 dtex, was knitted to obtain a knitted fabric. The knitted fabric had fabric weight of 225 g/m2, thickness of 1.65 mm, apparent density of 0.4 g/cm3 and air permeability of 320 cm3/cm2-seconds. The knitted fabric was carbonized from room temperature to 930degreesC in an inert atmosphere for 30 minutes. The carbonized fabric was activated for 90 minutes at 930degreesC in an atmosphere containing water vapor (12 mass%) to obtain activated carbon cloth (support). The activated carbon cloth had dry fabric weight of 103 g/m2, thickness of 1 mm, air permeability of 330 cm3/cm2-second, toluene adsorption property of 54 g/m2 and specific surface area of 1620 m2/g as determined by Brunauer Emmett Teller (BET) method. The activated carbon cloth was heat processed for 2 minutes to obtain a yield of 99 mass%. The processed cloth had dry fabric weight of 102 g/m2, thickness of 1 mm, air permeability of 330 cm3/cm2-second, toluene adsorption property of 53 g/m2, BET specific surface area of 1620 m2/g, and surface acidic functional group (1.2%) as measured by X-ray photoelectron spectroscopy analysis. The fibrous activated carbon cloth was immersed to an aqueous solution of a chloroplatinic acid, to obtain 5% mass platinum-catalyst supported activated carbon. The platinum-catalyst supported activated carbon had adsorption property of 44 g/m2, BET specific surface area of 1330 m2/g, air permeability of 330 cm3/cm2-second, and generated hydrogen at a rate of 5.2 l/minute.