A semiconductor device includes a source/drain region in a fin-type active pattern, a gate structure adjacent to the source/drain region, and an insulating layer on the source/drain region and the gate structure. A shared contact plug penetrates through the insulating layer and includes a first lower portion connected to the source/drain region, a second lower portion connected to the gate structure, and an upper portion connected to upper surfaces of the first lower portion and the second lower portion. A plug spacer film is between the insulating layer and at least one of the first lower portion and the second lower portion and includes a material different from a material of the insulating layer.