Sintered body and electrode, method for surface densitication of these, process for manufacturing electrode by this method and circuit breaker

This application is based on Japanese Patent Application No. 2001-216589 filed in Japan, the contents of which are incorporated hereinto by reference. An electrode comprises an electrode main body having a porosity, and the conductivity of the electrode main body at its part ranging from the arc running face to a stated depth is made higher than the conductivity at the section or the conductivity at the part ranging from the back surface to a stated depth. This brings about an improvement in circuit-break performance of a circuit breaker and also prevents the arc running face of the electrode main body from deteriorating.