Abstract: A polarizing electrode for an electric double layer capacitor has good moldability and can achieving higher density of electrode and higher capacity, and an electric double layer capacitor employs the same. The electric double layer capacitor is made of an activated carbon obtained by activating a hard-to-graphitize material (for example, phenol resin) with water vapor, and the activated carbon has a median particle size within a range from 4 &mgr;m to 8 &mgr;m in the particle size distribution and at least a peak observed on the side of smaller particle size than the median particle size in the particle size distribution.

Abstract: A method of producing a cyclized polydiene comprising cyclizing a polydiene in an organic solvent with the aid of a binary catalyst comprising tin halide or titanium halide and an organosulfonic acid or a haloacetic acid. The method provides a cyclized polydiene having a narrow molecular weight distribution in a short reaction time and with high reproducibility. The method does not entail side reactions causing gelation or discoloration.