A semiconductor device includes a substrate having a fuse area and a device area; a fuse structure in an insulating layer of the fuse area, and a wire structure in the insulating layer of the device area. The fuse structure includes a fuse via, a fuse line electrically connected to a top end of the fuse via pattern and extending in a direction. The wire structure includes a wire via, a wire line electrically connected to a top end of the wire via and extending in the first direction. A width in the first direction of the fuse via is smaller than a width in the first direction of the wire via.