Provided is a semiconductor device. The semiconductor device includes an isolation region disposed in a semiconductor substrate and configured to define an active region. A gate electrode buried in the active region is disposed. A gate dielectric layer is disposed between the active region and the gate electrode. A first source/drain region and a second source/drain region are disposed in the active region on both sides of the gate electrodes. An interconnection structure intersecting with the gate electrode, overlapping the first and second source/drain regions, electrically connected with the first source/drain region, and spaced apart from the second source/drain region is disposed. A contact structure is disposed on the second source/drain region.