In activated carbon obtained by subjecting a carbonaceous material to an activation treatment, the overall content of alkali metals is set at 100 ppm or less, or the overall content of heavy metals is set at 20 ppm or less and the overall content of alkali...

Activated carbon useful as polarizable electrode material for an electric double-layer capacitor can be obtained by mixing a carbonaceous material and an alkali metal hydroxide while maintaining a solid state, granulating the obtained mixture while maintai...