An inverter includes a power substrate mounting power element groups arranged apart from each other, each power element group constituted by power elements arranged, a control substrate disposed apart from the power substrate in a plate thickness direction of the power substrate and mounting an electronic component for controlling the power elements, a capacitor substrate disposed between the power substrate and the control substrate and mounting capacitors, a release member fixed to the power substrate, and a spacer electrically connecting the power substrate and the capacitor substrate. The spacer includes a body portion disposed between two adjacent power element groups of the power element groups and a heat transfer portion disposed outside the power element groups in a direction in which the power elements are arranged and provided at a position not overlapping with the capacitors as viewed in a plate thickness direction of the capacitor substrate.