A master battery management unit for a battery pack, the battery pack including a plurality of battery modules and a plurality of slave battery management units installed in the plurality of battery modules one-to-one, the master battery management unit comprising: a sensing unit configured to detect an electrical parameter including pack voltage of the battery pack, and generate pack information based on the detected electrical parameter; a first master power supply unit configured to generate a first operating voltage using the pack voltage supplied from the plurality of battery modules; a communication unit including an antenna and a wireless communication circuit operably connected to each other, and configured to operate using the first operating voltage supplied from the first master power supply unit, and output a first switching signal in response to the first operating voltage; a second master power supply unit configured to generate a second operating voltage using the pack voltage supplied from the plurality of battery modules in response to the first switching signal; and a control unit configured to operate using the second operating voltage supplied from the second master power supply unit, and test a preset item based on at least one of the pack information and module information from the plurality of slave battery management units, wherein the control unit is configured to stop outputting the first switching signal and output a second switching signal that is independent of the first switching signal when the control unit is electrically connected to an auxiliary power source provided in an object in which the battery pack is mounted, and the first master power supply unit is configured to stop generating the first operating voltage supplied for operation of the communication unit in response to the second switching signal. a sensing unit configured to detect an electrical parameter including pack voltage of the battery pack, and generate pack information based on the detected electrical parameter; a first master power supply unit configured to generate a first operating voltage using the pack voltage supplied from the plurality of battery modules; a communication unit including an antenna and a wireless communication circuit operably connected to each other, and configured to operate using the first operating voltage supplied from the first master power supply unit, and output a first switching signal in response to the first operating voltage; a second master power supply unit configured to generate a second operating voltage using the pack voltage supplied from the plurality of battery modules in response to the first switching signal; and a control unit configured to operate using the second operating voltage supplied from the second master power supply unit, and test a preset item based on at least one of the pack information and module information from the plurality of slave battery management units, wherein the control unit is configured to stop outputting the first switching signal and output a second switching signal that is independent of the first switching signal when the control unit is electrically connected to an auxiliary power source provided in an object in which the battery pack is mounted, and the first master power supply unit is configured to stop generating the first operating voltage supplied for operation of the communication unit in response to the second switching signal.