An end of a high-voltage electrode (5) is connected to a high-voltage terminal of a semiconductor device (1). An end of a low-voltage electrode (6) is connected to a low-voltage terminal of the semiconductor device (1). A resin (15) seals the semiconductor device (1), the end of the high-voltage electrode (5), and the end of the low-voltage electrode (6). A first discharge electrode (16) is provided to a portion of the high-voltage electrode (5) not covered by the resin (15). A second discharge electrode (17) is provided to a portion of the low-voltage electrode (6) not covered by the resin (15). The first and second discharge electrodes (16,17) protrude to face each other.