A capacitor structure includes a plurality of bottom electrodes horizontally spaced apart from each other, a support structure covering sidewalls of the bottom electrodes, a top electrode surrounding the support structure and the bottom electrodes, and a dielectric layer interposed between the support structure and the top electrode, and between the top electrode and each of the bottom electrodes. An uppermost surface of the support structure is positioned at a higher level than an uppermost surface of each of the bottom electrodes.