Provided herein is an interlock apparatus for preventing the drawing-in or drawing-out of a vacuum circuit breaker main body in interlock with the ground operation of a ground switch in a vacuum circuit breaker, and the ground switch interlock apparatus of the vacuum circuit breaker comprising: a drive spindle; a movable plate movable to a manipulation handle connection allowance position or a manipulation handle connection prohibition position; a first interlock plate that moves the movable plate to the manipulation handle connection allowance position or the manipulation handle connection prohibition position; and a second interlock plate to be moved to a position for locking the first interlock plate at the manipulation handle connection prohibition position when the ground switch is at a ground position and a position for releasing from the restraint of the first interlock plate when the ground switch is not at the ground position.