Coffee residue, a biomass, was used as an important source of precursors for thepreparation of activated carbon by a chemical activation method. Activated carbon fromcoffee residue was prepared in a two-step process: carbonization and chemicalactivation processes. The influence of the activation condition variables such asactivation reagents, activation reagent/precursor ratios, activation temperatures andactivation times were investigated to find the optimum conditions. The quality of thederived activated carbon is characterized in terms of its physical properties ofadsorption using different analytical methods for liquid and gas phase adsorption. Forthe gas adsorption test, the surface area and total pore volume of the derivedactivated carbons were measured by Nitrogen Adsorption Isotherms at 77 K (BETmethod), using an Autosorp (BEL MINISORP). The liquid adsorption test, theadsorption quality of the derived activated carbon, was evaluated in terms of iodineadsorption capacity (Iodine Number) reflecting the surface area. The optimumcondition from experimental results was ZnCl2/Coffee weight ratio of 3:1, an activationtemperature of 500 oC and activation time of 2 hrs. The characteristics of the derivedactivated carbon produced under optimum conditions were an iodine number of 926mg/g, BET surface area of 1,218.18 m2/g, and total pore volume of 0.86 cm3/g. Thenitrogen adsorption isotherm of the derived activated carbon exhibits Type I.Furthermore, the commercial activated carbons used to compare the adsorptionquality, the surface area, the pore structure and iodine number with coffee residueactivated carbon were reported. Activated carbons obtained from coffee residueshowed good qualities for use as an activated carbon because iodine numbers are higher than 600 mg/g and the moisture content (%) is less than 8%, valuesconsidered by the Thai Industrial Standards Institute, TISI.900-2004.