A rectifier device which includes a first radiating fin, a flat type semiconductor element which is disposed in contact with one surface of said first radiating fin, a substantially cylindrical insulating envelope which envelopes the flat type semiconductor element and one side of which is coupled with said first radiating fin, a second radiating fin which is coupled with the other side of the insulating envelope, and a through conductor which is threadably inserted through a central part of said second radiating fin and which lies in contact with said flat type semiconductor element.
