A semiconductor device includes a substrate having a cell region and a peripheral region surrounding the cell region, a lower electrode extending in a vertical direction on the cell region of the substrate, an upper electrode surrounding a sidewall and a top surface of the lower electrode, a capacitor dielectric layer disposed between the lower electrode and the upper electrode, a first barrier layer disposed on the upper electrode, the first barrier layer in contact with each of a sidewall and a top surface of the upper electrode, a first interlayer insulating layer covering the first barrier layer, the first interlayer insulating layer including a material different from the first barrier layer, and a first contact penetrating through the first barrier layer and the first interlayer insulating layer in the vertical direction, the first contact connected to the upper electrode.