A vacuum circuit breaker is such kind of circuit breaker where the arc quenching takes place in vacuum. The technology is suitable for mainly medium voltage application. For higher voltage vacuum technology has been developed but not commercially viable. The operation of opening and closing of current carrying contacts and associated arc interruption take place in a vacuum chamber in the breaker which is called vacuum interrupter. Service life of vacuum circuit breaker is much longer than other types of circuit breakers. There is no chance of fire hazard in vacuum circuit breaker as oil circuit breaker. It is much environment friendly than SF6 Circuit breaker. Beside of that contraction of VCB is much user friendly. Replacement of vacuum interrupter (VI) is much convenient.