Semiconductor device

Main electrodes (M10, M20, M30) are almost aligned along the length of a resin case (1). The main electrodes (M10, M20, M30) each have one main surface (inside main surface) facing the inside of the case body (101), where the insulating substrates (3A, 3B) are provided, and the other main surface (outside main surface) facing the outside of the case body (101), opposite to the side where the insulating substrates (3A, 3B) are provided. A conductor (4) is so disposed as to be opposed to the outside main surfaces of the main electrodes (M10, M20, M30). Having this configuration, a semiconductor device is provided, which enables reduction of the self-inductance without parallel arrangement of the main electrodes, achieves a high switching characteristic and ensures a stable operation and high reliability.