A method for fabricating a vertical channel type non-volatile memory device including a plurality of memory cells stacked along channels protruding from a substrate includes: alternately forming a plurality of first material layers and a plurality of second material layers over the substrate; forming a buffer layer over the substrate with the plurality of the first material layers and the plurality of the second material layers formed thereon; forming trenches by etching the buffer layer, the plurality of the second material layers, and the plurality of the first material layers; forming a material layer for channels over the substrate to fill the trenches; and forming the channels by performing a planarization process until a surface of the buffer layer is exposed.