To provide a screw ensuring proper fastening strength using a screwdriver capable of fastening even phillips screws, while solving the problem wherein the heads of slot and phillips screws are likely to be deformed making it difficult to do work at deep parts and to provide a V-slot screw enabling work at deep parts and being usable with conventional screwdrivers.

The V-slot screw A provided with a slot at the top of a V-slot to enable use of a conventional flathead screwdriver has a sufficiently large contact area so that, using a screwdriver B for work at deep parts, it enables work at deep parts. The V-slot screw A1 permits proper fastening, with the screwhead resistant to deformation, since a force is evenly applied by a V-slot-screw fastening driver D capable of handling phillips screws.