A semiconductor device includes an embedding layer in which one or more semiconductor element(s) is embedded and one or more interconnect layers as well as one or more insulation layers on one or both sides of the embedding layer. The embedding layer includes a woven cloth formed by reinforcement fibers. The woven cloth has an opening on its site embedding the semiconductor element. The opening is arranged so that direction of the reinforcement fibers will have a preset angle with respect to a direction of a side of or a tangent to at least a portion of the opening, the preset angle being other than a square angle or a zero angle (parallelism).