A semiconductor device includes a fin region with long and short sides, a first field insulating layer including a top surface lower than that of the fin region and adjacent to a side surface of the short side of the fin region, a second field insulating layer including a top surface lower than that of the fin region and adjacent to a side surface of the long side of the fin region, an etch barrier pattern on the first field insulating layer, a first gate on the fin region and the second field insulating layer to face a top surface of the fin region and side surfaces of the long sides of the fin region. A second gate is on the etch barrier pattern overlapping the first field insulating layer. A source/drain region is between the first gate and the second gate, in contact with the etch barrier pattern.