A semiconductor device has an island portion on which a semiconductor chip is adhered through intermediation of an insulating paste. Recessed portions having an inverted pyramid shape are formed in a semiconductor chip placing region of the island portion. A first opening angle formed by a normal extending upward from a vertex of each of the plurality of recessed portions each having an inverted pyramid shape and an opening line extending to an outer side of the semiconductor chip placing region is smaller than a second opening angle formed by the normal and an opening line extending to an inner side of the semiconductor chip placing region.