PURPOSE: To increase the switching speed and thus make it difficult to generate information error write by a method wherein a means of reducing an electric field impressed on a channel region, when a potential difference is impressed between both of the following regions, is provided on either one of a source and a drain region.

CONSTITUTION: A field insulation film 22 is provided at the field part of a p type Si substrate 21. An n+ type region 23 serving as the source or the drain region is provided on the surface of the substrate 21 surrounded by the film 22. In the same manner, an n+ type region 24 of a high concentration and an n type region 25 of a low concentration are provided. Then, the region 25 is provided on the side close to the region 23 and the channel region 27. A gate insulation film 28 is provided on the surface of the substrate 21 surrounded by the film 22, and a floating gate 29 composed of polycrystalline Si is provided thereon. Further, an insulation film 30 is provided thereon, and a control gate 31 is provided thereon.