Conventionally, conductivity has been imparted to rubbers, resins or the like by containing carbon black therein. In particular, acetylene black has a chain structure of spherical carbon particles, and therefore has excellent conductivity-imparting ability as compared with general carbon black. For this reason, acetylene black is widely used. However, recently it is required to impart far high conductivity to resins or the like. Further, the maximum amount of carbon black that can be compounded without deteriorating inherent physical properties of resins or the like is substantially fixed. In view of those facts, it is considered at the present stage the only way to satisfy the requirement is to develop carbon black having markedly excellent conductivity-imparting ability.