A vehicle-air-conditioner electric compressor comprising: an electric motor; a compressing mechanism; a pressure-resistant housing in which the electric motor and the compressing mechanism are accommodated; an inverter accommodating section arranged at the periphery of the pressure-resistant housing; an inverter which is incorporated in the inverter accommodating section, the inverter converting direct-current power supplied from a high-voltage power source to three-phase alternating-current power and including glass-sealed terminals that feeds the power to the electric motor in the pressure-resistant housing, the vehicle-air-conditioner electric compressor being suitable for being mounted to a vehicle in a vehicle-mounted state wherein a motor axis of the electric motor is oriented in the lateral direction of the vehicle, the inverter accommodating section and the inverter are offset to the rear of the vehicle with respect to the front-surface portion, facing the front of the vehicle, of the pressure-resistant housing, and the inverter accommodating section and the inverter are offset in a direction perpendicular to the motor axis with respect to the front-surface portion of the pressure-resistant housing, the front-surface portion being parallel to the motor axis, wherein the inverter includes an inverter module in which a power board provided with a power semiconductor switching device and a power-system control circuit for operating the switching device and a CPU board provided with control and communication circuits having devices that operate at low voltage, such as a CPU, are modularized; the inverter module includes a plurality of mounting legs for fixing a module main body by screws to the inverter accommodating section and the pressure-resistant housing; characterized in that the mounting legs are offset with respect to the module main body and are fixed by screws to the inverter accommodating section and the pressure-resistant housing at substantially equal distances on either side of the motor axis. an electric motor; a compressing mechanism; a pressure-resistant housing in which the electric motor and the compressing mechanism are accommodated; an inverter accommodating section arranged at the periphery of the pressure-resistant housing; an inverter which is incorporated in the inverter accommodating section, the inverter converting direct-current power supplied from a high-voltage power source to three-phase alternating-current power and including glass-sealed terminals that feeds the power to the electric motor in the pressure-resistant housing, the vehicle-air-conditioner electric compressor being suitable for being mounted to a vehicle in a vehicle-mounted state wherein a motor axis of the electric motor is oriented in the lateral direction of the vehicle, the inverter accommodating section and the inverter are offset to the rear of the vehicle with respect to the front-surface portion, facing the front of the vehicle, of the pressure-resistant housing, and the inverter accommodating section and the inverter are offset in a direction perpendicular to the motor axis with respect to the front-surface portion of the pressure-resistant housing, the front-surface portion being parallel to the motor axis, wherein the inverter includes an inverter module in which a power board provided with a power semiconductor switching device and a power-system control circuit for operating the switching device and a CPU board provided with control and communication circuits having devices that operate at low voltage, such as a CPU, are modularized; the inverter module includes a plurality of mounting legs for fixing a module main body by screws to the inverter accommodating section and the pressure-resistant housing; characterized in that the mounting legs are offset with respect to the module main body and are fixed by screws to the inverter accommodating section and the pressure-resistant housing at substantially equal distances on either side of the motor axis.