A cover for protecting a large number of electric wires in the housing in a bolt-screwed high-density multi-pole connector having a screw bolt. The cover is plate-shaped. The cover has an engagement hole corresponding to a bolt holder having a rectangular cylinder into which the screw bolt is inserted and a handle provided at one end where the electric wires are fixed and from which they are extracted. Thus, the cover can be easily mounted on the housing. With no fear of catching or breaking of electric wires, the direction of extracting the electric wires can be optionally selected. Further, the cover can be fabricated at low cost.