The present technology includes a semiconductor memory device. The semiconductor memory device includes a first channel pattern and a second channel pattern each extending in a vertical direction and facing each other, a channel separation pattern formed between the first channel pattern and the second channel pattern and extending in the vertical direction, a stack including conductive patterns each surrounding the first channel pattern, the second channel pattern, and the channel separation pattern and stacked apart from each other in the vertical direction, a first memory pattern disposed between each of the conductive patterns and the first channel pattern, and a second memory pattern disposed between each of the conductive patterns and the second channel pattern.