Abstract: A non-volatile memory device including a substrate including a first area and a second area, a mold structure on the substrate, the mold structure including gate electrodes and mold insulating films alternately stacked on each other in a stepwise manner, an interlayer insulating film covering the mold structure, a channel structure on the first area, the channel structure extending through the mold structure and connected to the gate electrodes, and a through-contact on the second area and extending through the interlayer insulating film, the through-contact including a first portion in a first trench and a second portion in a second trench, the first portion including a liner film along a sidewall and a bottom surface of the first trench and a filling film on the liner film, wherein the filling film being a multi-grain conductive material, and the second portion being a single grain conductive material, may be provided.