A gate formed in a peripheral region is buried in a semiconductor device such that bit line contact plugs respectively coupled to an active region and the gate are simultaneously formed and a short-circuit between the gate and the bit line contact plug is prevented, thereby improving the characteristics of the device. The method of manufacturing the semiconductor device includes forming a gate buried in a semiconductor substrate, and forming a first bit line contact plug coupled to the gate and a second bit line contact plug coupled to the semiconductor substrate.