The effect of activation temperature on the structural properties and the electrochemical performance of KOH-activated carbon xerogel was investigated in range of 700 to 1000 ∘ C. At a high temperature (1000 ∘ C), the chemical activation regenerated a more crystalline network structure of activated carbon xerogels, which was observed by Raman, XRD, and TEM images. Additionally, SEM images, BET, BJH, and -plot were used to study the structural properties of carbon xerogels. The carbon xerogel sample activated at 900 ∘ C was found with the most appropriate structure, which has the high micropore area and a more-balanced porosity between the micropores and mesopores, for using as an electrode material. The highest obtained specific capacitance value was 270 Fg −1 in 6 M KOH electrolyte at scan rate of 5 mVs −1 from the cyclic voltammetry.