To provide a semiconductor memory device which can be readily increased in packing density, and to provide method for manufacturing the same.

The semiconductor memory device 20 has a structure which includes a second conductivity purity diffusion region 6 on the surface of the first conductivity semiconductor substrate 20, the second conductivity being opposite to the first conductivity, a floating gate electrode 9 formed on the semiconductor substrate 20 via a gate insulating film 7, and a control gate electrode 11 formed on the floating gate electrode 9 via an inter-electrode insulating film 10. Here, the gate insulating film 7 is formed on the surface of the semiconductor substrate 20, excepting the impurity diffusion region 6 and the third insulating film 5 thicker than the gate insulating film 7 is formed on the surface of the impurity diffusion region 6, and the floating gate electrode 9 is extended on the sidewall of the third insulating film 5.