A method of manufacturing a semiconductor device has forming a first conductive film over a semiconductor substrate, etching the first conductive film, forming a plurality of first conductive patterns arranged in a first direction, and forming a side surface on an outside of a conductive pattern positioned at an end among the plurality of first conductive patterns such that the side surface has a first inclination angle smaller than a second inclination angle of a side surface on an inside of the conductive pattern positioned at the end, forming a first insulation film over the plurality of first conductive patterns, and forming a second conductive pattern over the first insulation film.