A power converter (2; 2a; 2b; 2c; 2d) comprising: two switching elements (6, 7) connected in series; a positive electrode conductive plate (13; 113) connected to a high-potential terminal of a series connection of the two switching elements (6, 7); a negative electrode conductive plate (14; 114) connected to a low-potential terminal of the series connection of the two switching elements (6, 7); a mid-point conductive plate (15; 115a; 115b) connected to a middle point of the series connection of the two switching elements (6, 7); a first heat sink (18; 118; 218; 318; 418) having electric conductivity, the first heat sink (18; 118; 218; 318; 418) facing the positive electrode conductive plate (13; 113) with a first isolating layer (31; 131) interposed between the first heat sink (18; 118; 218; 318; 418) and the positive electrode conductive plate (13; 113), the first heat sink (18; 118; 218; 318; 418) facing the negative electrode conductive plate (14; 114) with the first isolating layer (31; 131) interposed between the first heat sink (18; 118; 218; 318; 418) and the negative electrode conductive plate (14; 114), and the first heat sink (18; 118; 218; 318; 418) being connected to a ground terminal maintained at a ground potential; and a second heat sink (19; 119; 219; 319; 419) having electric conductivity, the second heat sink (19; 119; 219; 319; 419) facing and supporting the mid-point conductive plate (15; 115a, 115b) with a second isolating layer (31, 133) interposed between the second heat sink (19; 119; 219; 319; 419) and the mid-point conductive plate, the second heat sink (19; 119; 219; 319; 419) being isolated from the ground terminal. two switching elements (6, 7) connected in series; a positive electrode conductive plate (13; 113) connected to a high-potential terminal of a series connection of the two switching elements (6, 7); a negative electrode conductive plate (14; 114) connected to a low-potential terminal of the series connection of the two switching elements (6, 7); a mid-point conductive plate (15; 115a; 115b) connected to a middle point of the series connection of the two switching elements (6, 7); a first heat sink (18; 118; 218; 318; 418) having electric conductivity, the first heat sink (18; 118; 218; 318; 418) facing the positive electrode conductive plate (13; 113) with a first isolating layer (31; 131) interposed between the first heat sink (18; 118; 218; 318; 418) and the positive electrode conductive plate (13; 113), the first heat sink (18; 118; 218; 318; 418) facing the negative electrode conductive plate (14; 114) with the first isolating layer (31; 131) interposed between the first heat sink (18; 118; 218; 318; 418) and the negative electrode conductive plate (14; 114), and the first heat sink (18; 118; 218; 318; 418) being connected to a ground terminal maintained at a ground potential; and a second heat sink (19; 119; 219; 319; 419) having electric conductivity, the second heat sink (19; 119; 219; 319; 419) facing and supporting the mid-point conductive plate (15; 115a, 115b) with a second isolating layer (31, 133) interposed between the second heat sink (19; 119; 219; 319; 419) and the mid-point conductive plate, the second heat sink (19; 119; 219; 319; 419) being isolated from the ground terminal.