A semiconductor device includes a memory component, which is a semiconductor component (a semiconductor chip or a semiconductor package), to be mounted over an upper surface of a wiring substrate. In addition, in the upper surface, a distance between the memory component and a first substrate side of the upper surface is smaller than a distance between the memory component and a second substrate side of the upper surface. In addition, in the upper surface, a dam portion is formed between the memory component and the first substrate side.