Semiconductor device includes a pair of substrates (1, 2) disposed oppositely, semiconductor elements (5, 6) formed in the substrates (1, 2), respectively, and having semiconductor circuits (3, 4) and electrodes (7, 8), respectively, a wiring conductor (9) interposed between the electrodes (7, 8), and a through electrode (12) extending through one substrate (1) and connected to the electrode (7) via the wiring conductor (9). The other substrate (2) is disposed laterally of the through electrode (12). Surface of the through electrode (12) projecting from the one substrate (1) and lateral surface of the element (6) are coated with an insulation material (13). The through electrode (12) has one end exposed in a back surface of the one substrate (1), while other end is positioned flush with a back surface of the other substrate (2), being exposed.