A semiconductor device includes a plurality of first gate electrodes buried in a semiconductor substrate including an active region and a device isolation film, a plurality of junction regions including storage node junction regions and a bit line junction region disposed between the storage node junction regions, a plurality of storage node contact plugs respectively disposed over and coupled to the storage node junction regions, a plurality of storage nodes respectively disposed over and coupled to the storage node contact plugs, and a second gate electrode disposed over a sidewall of a corresponding one of the storage node contact plugs. A vertical transistor includes the second gate electrode and the corresponding storage node contact plug and stores charges leaked from a corresponding one of the storage nodes.