A method of manufacturing a semiconductor device includes sequentially stacking a mold layer and a supporter layer on a substrate, forming a plurality of capacitor holes passing through the mold layer and supporter layer, forming a plurality of lower electrodes filling the capacitor holes, forming a supporter mask pattern having a plurality of mask holes on the supporter layer and the lower electrodes, and forming a plurality of supporter holes by patterning the supporter layer. Each of the plurality of lower electrodes has a pillar shape, and each of the mask holes is between four adjacent lower electrodes and has a circular shape.