VERTICAL MEMORY DEVICE

A memory device may include word line patterns stacked on a substrate and spaced from each other in a vertical direction, a channel structure extending in the vertical direction, and first contact plugs and second contact plugs extending in the vertical direction. The substrate includes a cell area, a cell wiring area, and a through-hole wiring area. The word line patterns may be on the cell area and may extend to the cell wiring area in a direction parallel to an upper surface of the substrate. The first contact plugs may be on the cell wiring area and each may be electrically connected with a corresponding one of the word line patterns and insulated from remaining word line patterns. The second contact plugs may be on the through-hole wiring area and at least one of the second contact plugs is electrically connected with a part of the word line patterns.