A method for preparing a carbon microparticle from an organic raw material having lignin as a main constituent, wherein an aqueous solution with 5% total concentration of lignin and sodium hydroxide (the proportion in mass is 1:0.5) is spray-dried to prepare a complex microparticle. This complex microparticle is heat-processed under nitrogen atmosphere at 600° C. for one hour and cooled. Thereafter, this is washed with water and further dried to prepare a hollow carbon microparticle such as those shown in FIG. 2 (b). The prepared carbon microparticle is light-weight and has an equivalent specific surface area to commercially available activated charcoal.