PURPOSE: To improve write efficiency by enabling channel hot electrons to be injected into a floating gate from the inversion layer controlled by the first electrode.

CONSTITUTION: A first insulating film (gate oxide film) 2, a tunnel insulating film 9, a first electrode (auxiliary gate) 4, a floating gate 11a, and a second electrode (control gate) 13 are provided on a p-type Si substrate 1. And, the first electrode 4 is made on the first insulating film 2, whereby write can be performed by channel hot electrons being injected into a floating gate 11a from the inversion layer made under the first electrode 4 of the floating gate 11a and controlled by the first electrode 4. Hereby, write efficiency is improved.