An inverter-integrated electric compressor enhances vibration resistance of an inverter apparatus integrated with a housing without degrading cooling performance, reduction in weight, or the ease of assembly of the inverter apparatus. An inverter-integrated electric compressor has an inverter apparatus integrated with an inverter storage box of housing. The inverter apparatus includes a metal plate secured in an inverter storage box, a plurality of power semiconductor switching elements mounted on the metal plate, a power substrate on which a power-related control circuit for operating the power semiconductor switching elements is mounted, and a busbar assembly formed by integrating a plurality of busbars with an insulator. The metal plate includes a protrusion extending in a width direction perpendicular to a motor shaft direction of an electric motor.