An inverter-charger combined device configured to charge a high voltage battery in case of charging mode, and drive a 3-phase motor by switching a power of the high voltage battery in case of operation mode, the device comprising: a rectifier providing a power for charging the high voltage by rectifying an inputted AC power; an inverter receiving the AC power rectified by the rectifier via the 3-phase motor in case of charging mode to rectify the AC power to a DC power, and converting the DC power charged in the high voltage battery in case of operation mode to drive the 3-phase motor; and a power supply unit supplying a power to drive the rectifier and the inverter: characterized by further comprising: a first switching unit; and a second switching unit; wherein, at default state, the power supply unit includes a first power supply unit for supplying a power to drive a switching unit of the rectifier and a second power supply unit for supplying a power to drive a switching unit of the inverter? the default state corresponds to the state where both first and second power supplies operate normally, wherein the first switching unit selects the first power supply unit or the second power supply unit to supply a power to drive the switching unit of the rectifier; and wherein the second switching unit selects the first power supply unit or the second power supply unit to supply a power to drive the switching unit of the inverter, and wherein the first switching unit and the second switching unit are configured to supply a power to the switching unit of the rectifier and the switching unit of the inverter from the second power supply unit by selecting the second power supply unit in case of failure at the first power supply unit, and to supply a power to the switching unit of the rectifier and the switching unit of the inverter from the first power supply unit by selecting the first power supply unit in case of failure at the second power supply unit. a rectifier providing a power for charging the high voltage by rectifying an inputted AC power; an inverter receiving the AC power rectified by the rectifier via the 3-phase motor in case of charging mode to rectify the AC power to a DC power, and converting the DC power charged in the high voltage battery in case of operation mode to drive the 3-phase motor; and a power supply unit supplying a power to drive the rectifier and the inverter: characterized by further comprising: a first switching unit; and a second switching unit; a first switching unit; and a second switching unit; wherein, at default state, the power supply unit includes a first power supply unit for supplying a power to drive a switching unit of the rectifier and a second power supply unit for supplying a power to drive a switching unit of the inverter? the default state corresponds to the state where both first and second power supplies operate normally, wherein the first switching unit selects the first power supply unit or the second power supply unit to supply a power to drive the switching unit of the rectifier; and wherein the second switching unit selects the first power supply unit or the second power supply unit to supply a power to drive the switching unit of the inverter, and wherein the first switching unit and the second switching unit are configured to supply a power to the switching unit of the rectifier and the switching unit of the inverter from the second power supply unit by selecting the second power supply unit in case of failure at the first power supply unit, and to supply a power to the switching unit of the rectifier and the switching unit of the inverter from the first power supply unit by selecting the first power supply unit in case of failure at the second power supply unit.