An interlock device of a withdrawable arc eliminator includes: an arc eliminator body; and a carriage module configured to move the arc eliminator body, wherein the carriage module includes: an insertion and withdrawal screw; a truck moved by the insertion and withdrawal screw; a movable pin installed at part of the truck so as to be moveable up and down; and a movable pin lifter backwardmoved by being pushed by a handle for rotating the insertion and withdrawal screw, and configured to upward-move the movable pin, and wherein the arc eliminator body includes: a housing having a space; an arc extinguisher installed at the housing, and including a moving rod disposed to move to the space back and forth; a fixed body disposed at the space, and having an insertion opening for inserting the movable pin thereinto; an interlock body disposed to be moveable to a first position between the insertion opening and the movable pin, and a second position except for the first position between the insertion opening and the movable pin; and an interlock body moving member operated by interworking with the moving rod, and configured to move the interlock body to the first position or the second position.