A semiconductor device includes a bit line extending in a first direction, a gate electrode extending in a second direction, and a semiconductor pattern extending in a third direction and connected to the bit line, and a capacitor. The capacitor includes a first electrode connected to the semiconductor pattern and a dielectric film between the first and second electrodes. The first or the second direction is perpendicular to an upper surface of the substrate. The first electrode includes an upper and a lower plate region parallel to the upper surface of the substrate, and a connecting region which connects the upper and the lower plate regions. The upper and the lower plate regions of the first electrode include an upper and a lower surface facing each other. The dielectric film extends along the upper and the lower surfaces of the upper and lower plate regions of the first electrode.