A semiconductor device includes a lower substrate having at least one
wiring pattern formed of a plurality of wirings, a semiconductor chip
positioned above the lower substrate and electrically connected to the
wirings, an intermediate member which seals the semiconductor chip in
columnar form and substantially, and an upper plate which substantially
covers a whole upper surface of the intermediate member. A thermal
expansion coefficient of the upper plate and a thermal expansion
coefficient of the lower substrate are set substantially identical.