Provided is a semiconductor device. The semiconductor device includes a capacitor structure including a plurality of lower electrodes, a dielectric layer that covers surfaces of the plurality of lower electrodes, and an upper electrode on the dielectric layer. The semiconductor device further includes a support structure that supports the plurality of lower electrodes. The support structure includes a first support region that covers sidewalls of one of the plurality of lower electrodes, and an opening that envelops the first support region when the semiconductor device is viewed in plan view.