To prevent injection of undesired hot carrier and occurrence of disturbance operation to operate stably, by forming a source-drain region on a substrate at least on the side of and a region adjacent to the protruding part of a semiconductor layer.

A control gate electrode 30a and a source-drain region are positioned with a difference in level, and electrical field concentration in the end of the control electrode can be controlled. Injection of undesired hot carrier into a charge accumulation layer CA and also degradation of the insulating film can be prevented. Further, a LDD diffusion layer 12a is formed in which conductive impurity is lightly doped into the side of a protruding part of a semiconductor layer, a source-drain diffusion layer 13a is formed in which conductive impurity is heavily doped into a semiconductor substrate 10 adjacent to the protruding part, and thus a LDD structure is constructed. As a result, injection of the undesired hot carrier and occurrence of disturbance can be further controlled.