Semiconductor device includes: substrate having substrate main surface and substrate rear surface facing opposite sides to each other in first direction, and substrate side surface facing in second direction orthogonal to the first direction; wiring layer having main surface electrode covering a portion of the substrate main surface, and side surface electrode connected to the main surface electrode and covering a portion of the substrate side surface; semiconductor element electrically connected to the main surface electrode and mounted on the substrate to face the substrate main surface; and sealing resin having resin side surface facing in the same direction as the substrate side surface, and covering the semiconductor element and the main surface electrode, wherein the side surface electrode has side exposed surface exposed from the sealing resin and facing in the same direction as the substrate side surface, the side exposed surface being flush with the resin side surface.