PURPOSE: To provide a title device which can execute write and erase of information without using step-up circuits and improves a tunnel oxide film.

CONSTITUTION: This device has a gate electrode structure buried in a P-type silicon substrate 11. A tunnel oxide film 16 is formed on the inner wall of a groove 15 formed in the surface of the P-type silicon substrate 11. Source and drain regions 18, 17 are separated by the groove 15 and electrically connected by a channel layer formed in the surface of the silicon substrate contacting the side wall of this groove 15. A floating gate electrode 19 is formed on the surface of the tunnel oxide film 16. A control gate electrode 20 is formed on the floating gate electrode 19 via an insulation layer. Write and erase actions are executed by current flowing between the source or drain region in a vicinity of the open edge of the groove 15 and the floating gate electrode.