To provide a manufacturing method of a semiconductor memory device, the method including forming contact plugs to be connected to a drain region or a source region of each of transistors, by using a SAC line technique of selectively etching an insulation layer that covers each of the transistors by using a mask having a line-shaped opening provided across the contact plugs. Each of the transistors constituting a sense amplifier that amplifies a potential difference between bit lines is a ring-gate transistor.