PURPOSE: To reduce parasitic capacitance between a gate and a drain, to prevent a short channel effect and a hot electron effect and to suppress punch-through between a source and the drain, by providing a low concentration region having the reverse conducting type with respect to a substrate at the side wall part of a gate insulating film.

CONSTITUTION: On a one-conducting type semiconductor substrate 1, first semiconductor layers 4 and 5 including low concentration impurities having the reverse conducting type are laminated. The first semiconductor layers 4 and 5 are selectively removed, and a groove part is formed. An insulating gate film 9 is embedded in the groove part. Said first semiconductor layers 4 and 5 are made to remain at a part, where the side wall of the gate 9 is in contact with an insulating film 8. At the other part around the layers, second semiconductor layers 6 and 7, which have the same conducting type with respect to the semiconductor 1 and have the impurity concentration higher than that of the substrate 1, are formed at deeper positions. Third semiconductor layers 2 and 3, which have the reverse conducting type with respect to the semiconductor substrate 1 and include high concentration impurities, are formed at upper shallow positions on the layers 6 and 7. Said third semiconductor layers 2 and 3, which are isolated by the insulating gate 9, are made to be a source and a drain. Thus a depletion layer, which is extended on the drain and the substrate, is suppressed. Punch-through is hard to occur even in a minute element.