A semiconductor device 1 is provided with: a semiconductor element 10, which has a semiconductor circuit 11 that is formed on a first main surface 10SA, and a via hole H10 having an opening in a second main surface 10SB; first wiring 21A, which is disposed on the first main surface 10SA of the semiconductor element 10, and a part of which is exposed from the bottom surface of the via hole H10, said first wiring being connected to the semiconductor circuit 11; a first insulating layer 22A covering the first wiring 21A; and rewiring 30 extending from a contact section 30A to an area on the second main surface 10SB via the inside of the via hole H10, said contact section being in contact with, at the bottom surface of the via hole H10, the first wiring 21A. A first through hole H21A is formed in the first wiring 21A, and the contact section 30A is in contact with a plurality of surfaces of the first wiring 21A.