A vehicle-air-conditioner electric compressor comprising a housing formed of a motor housing configured for accommodating an electric motor and a compressor housing configured for accommodating a compression mechanism; and an inverter unit including a high-voltage ground circuit area configured for driving the electric motor, a low-voltage ground circuit area configured for control and communication, high-voltage components (23, 24) and high-voltage cables (13, 14) configured for supplying a high voltage from a high-voltage power supply to a power system circuit on the high-voltage ground, and low-voltage cables and connectors (15, 16) configured for supplying a low voltage from a low-voltage power supply to the low-voltage ground circuit, the inverter unit being integrated with the housing and configured such that the low-voltage ground circuit area and the low-voltage ground circuit area are isolated from each other, wherein the inverter unit is accommodated in a substantially square-shaped inverter box integrated with a side where the electric motor is accommodated in the housing, and the compressor housing is located with respect to the motor housing on a positive side in a Z-axis direction, wherein the Z-axis direction is an axial direction of the electric motor in the inverter box, and a position of the inverter box with respect to the housing is on a positive side in a Y-axis direction, the Y-axis going through the housing and being perpendicular to a plane defined by the Z-axis and an X-axis perpendicular to the Z-axis, characterized in that in a case that a capacitor and an inductor as the high-voltage components are disposed along a side surface on the positive side in the X-axis, a lead-out position of the low-voltage cables and the connectors (15, 16) is provided in a side surface on the negative side in the X-axis direction in the inverter box opposite to the side surface on the positive side in the X-axis direction; or in a case that a capacitor and an inductor as the high-voltage components are disposed along a side surface on the negative side in the Z-axis direction in the inverter box, a lead-out position of the low-voltage cables and the connectors (15, 16) is provided in a side surface on the positive side in the Z-axis direction in the inverter box opposite to the side surface on the negative side in the Z-axis direction. wherein the inverter unit is accommodated in a substantially square-shaped inverter box integrated with a side where the electric motor is accommodated in the housing, and the compressor housing is located with respect to the motor housing on a positive side in a Z-axis direction, wherein the Z-axis direction is an axial direction of the electric motor in the inverter box, and a position of the inverter box with respect to the housing is on a positive side in a Y-axis direction, the Y-axis going through the housing and being perpendicular to a plane defined by the Z-axis and an X-axis perpendicular to the Z-axis, characterized in that in a case that a capacitor and an inductor as the high-voltage components are disposed along a side surface on the positive side in the X-axis, a lead-out position of the low-voltage cables and the connectors (15, 16) is provided in a side surface on the negative side in the X-axis direction in the inverter box opposite to the side surface on the positive side in the X-axis direction; or in a case that a capacitor and an inductor as the high-voltage components are disposed along a side surface on the negative side in the Z-axis direction in the inverter box, a lead-out position of the low-voltage cables and the connectors (15, 16) is provided in a side surface on the positive side in the Z-axis direction in the inverter box opposite to the side surface on the negative side in the Z-axis direction.