A memory device may include a bottom electrode, first and second switching elements over the bottom electrode, and first and second top electrodes over the first and second switching elements respectively. The first and second top electrodes may include first and second contact surfaces in contact with the first and second switching elements respectively. The first and second switching elements may each have a resistance configured to switch between resistance values in response to changes in voltages applied between the top electrodes and the bottom electrode. The bottom electrode may include at least one conductive layer having third and fourth contact surfaces in contact with the first and second switching elements respectively. An area of the first contact surface may be greater than an area of the third contact surface, and an area of the second contact surface may be greater than an area of the fourth contact surface.