A power converter apparatus includes a substrate 22 on which switching elements Q, Q1 to Q6 are mounted, positive and negative terminal interconnection members 27, 28 mounted on the substrate, and a capacitor 17 having a positive terminal 17a connected to the main body of the positive terminal interconnection member 27 and a negative terminal 17b connected to the main body of the negative terminal interconnection member 28. The interconnection members each have a plate-like main body 27a, 28a that is located above and parallel to the substrate 22. The main bodies of the interconnection members are stacked to be close to each other while being electrically insulated from each other. Each of the positive terminal interconnection member and the negative terminal interconnection member further includes a plate-like extension 27b, 28b that extends from the corresponding main body toward the substrate, and a terminal portion 27c, 28c that extends from the extension and is joined to the substrate. The extensions extend to positions closest to the substrate, while being parallel to and close to each other.