A semiconductor device according to an embodiment includes a gate stack structure and a channel structure. The gate stack structure includes a plurality of gate electrodes and a plurality of insulating layers alternately stacked on a substrate in a first direction perpendicular to an upper surface of the substrate. The channel structure includes a portion penetrating through the gate stack structure and extending in the first direction. The channel structure includes a channel layer, a resistance change layer, and a metal-containing layer sequentially stacked. The metal-containing layer includes a metal or a metal compound.