A vacuum circuit breaker includes: a grounded tank; a vacuum valve including a vacuum container housing a movable contact and a stationary contact, a movable conductor that is connected to the movable contact and extends out of the vacuum container, and a tubular bellows; a tubular movable-side bushing conductor; a slider movably set inside the movable-side bushing conductor; a movable-side frame that communicates with a space inside a tube of the bellows and electrically connects the movable-side bushing conductor to the movable conductor; an operation rod having one end protruding to an outside of the grounded tank and an opposite end connected to the movable conductor; an operating device that moves the operation rod; a movable-side support plate covering an end of the grounded tank where the operation rod extends out of the grounded tank; and a packing set in a hole.