The present invention provides a method for producing an activated carbon for an electric double layer capacitor, with which the wettability of a carbon material with an alkali activator is improved, thereby improving contact efficiency between the carbon material and the alkali activator and efficiently promoting reaction between the carbon material, which is a starting material and the activator. The method comprises adjusting a carbon material as it is or after having been calcined to produce a carbon powder having an average particle diameter of 0.5 to 15 μm, oxidizing the carbon powder to contain 3 percent by mass or more of oxygen, and activating the oxidized product with an alkali activator.