There is provided an integrated electric compressor that is improved in reliability. Bus bar connection is employed for electrical connection between a power board 16 and the power source side and between the power board 16 and the motor side, and welding is employed for joining a bus bar to a capacitor 13 and a reactor 14, for joining board-side terminal parts of the bus bar to PN terminals 20a and 20b, and for joining UVW terminals 25a, 25b and 25c to housing-side terminals 28a, 28b and 28c. By employing resistance welding for the welding, the terminals can be joined to each other with stabilized quality. Further, since flat joint plates are provided on one end side of the housing-side terminals 28a, 28b and 28c, and the UVW terminals 25a, 25b and 25c are welded thereto, reliable joints between terminals can also be attained in these portions.