A semiconductor device may include an active pattern on a substrate; an isolation pattern on the substrate, the isolation pattern covering opposite sidewalls of the active pattern; a liner on the isolation pattern, a liner including a material different from the isolation pattern; a gate structure contacting an upper surface of the active pattern and an upper surface of the liner; and a plurality of channels spaced apart from each other in a vertical direction perpendicular to an upper surface of the substrate, each of the plurality of channels extending through the gate structure.