A semiconductor device and a method of fabricating the same are provided. According to the present invention, a semiconductor device comprises an active region formed in a substrate, and including flat surfaces and hole-shaped recess portions; upper-level plugs disposed over the flat surfaces; a spacer disposed between the upper-level plugs and providing a trench exposing the hole-shaped recess portions; a lower-level plug filling the hole-shaped recess portions; and a buried conductive line disposed over the lower-level plug and partially filling the trench.