A method for manufacturing an electronic device includes forming a first source layer including a trench, forming a first sacrificial layer in the trench, forming a first structure over the first source layer, wherein the first structure includes first material layers and second material layers which are alternately stacked over the each other, forming first openings passing through the first structure and extending to the first sacrificial layer, forming first channel layers in the first openings, forming a slit passing through the first structure and extending to the first sacrificial layer, forming a second opening by removing the first sacrificial layer through the slit, and forming a second source layer in the second opening, wherein the second source layer is coupled to the first channel layers.