A vertical memory device includes lower circuit patterns, a second substrate, a capacitor, gate electrodes, and a channel. The lower circuit patterns are formed on a first substrate including first, second and third regions. Contact plugs are formed in the second region. Through vias are formed in the third region. The second substrate is formed on the lower circuit patterns. The capacitor is formed on the lower circuit patterns, and includes a first conductor, a dielectric layer structure, and a second conductor. The first conductor is spaced apart from the second substrate at the same height as the second substrate. The dielectric layer structure is formed on the first conductor. The second conductor is formed on the dielectric layer structure. The gate electrodes are spaced apart from each other on the second substrate in a vertical direction. The channel extends through the gate electrodes in the vertical direction.