Stacked semiconductor device and method of manufacturing thereof

A stacked-type semiconductor device has a reduced overall height and an improved reliability in the mechanical strength of the stacked structure. The semiconductor device also has an improved heat release characteristic. A first interposer has a surface on which first electrode pads are formed and a first semiconductor element is mounted with a circuit forming surface facing the first interposer. A second interposer has a surface on which second electrode pads are formed and a second semiconductor element is mounted with a circuit forming surface facing the second interposer. External connection terminals are provided on a surface of the second interposer opposite to the surface on which the second semiconductor element is mounted. The first and second interposers are electrically connected to each other by conductive members provided therebetween. A back surface of the first semiconductor element and a back surface of the second semiconductor element are fixed to each other by an adhesive.