A structure of a battery disconnection unit for an electric vehicle having a battery for providing DC power, a charger for converting AC power into DC power and for charging the battery with the DC power, and an inverter for converting DC power from the battery into AC power and for providing the converted AC power to a motor, the structure comprising: a first high voltage relay electrically connected between the battery and the inverter and switching to a position for supplying DC power supplied from the battery to the inverter or to a position for interrupting the supply of the corresponding DC power; and a second high voltage relay electrically connected between the charger and the battery and switching to a position for supplying DC power supplied from the charger to the battery or to a position for interrupting the supply of the corresponding DC power, characterized in that the structure further comprises: a printed circuit board including a printed wired circuit electrically connected to the second high voltage relay and providing a DC power supply path between the charger and the battery by having an input terminal connected to the charger and an output terminal connected to the battery; a substrate installed at an upper position higher than the printed circuit board to support the first and second high voltage relays; a metal bracket that supports the printed circuit board and the substrate at a lower side and operates as a heat sink radiating heat; and a band shaped rubber isolating member surrounding and elastically supporting the second high voltage relay. a first high voltage relay electrically connected between the battery and the inverter and switching to a position for supplying DC power supplied from the battery to the inverter or to a position for interrupting the supply of the corresponding DC power; and a second high voltage relay electrically connected between the charger and the battery and switching to a position for supplying DC power supplied from the charger to the battery or to a position for interrupting the supply of the corresponding DC power, characterized in that the structure further comprises: a printed circuit board including a printed wired circuit electrically connected to the second high voltage relay and providing a DC power supply path between the charger and the battery by having an input terminal connected to the charger and an output terminal connected to the battery; a substrate installed at an upper position higher than the printed circuit board to support the first and second high voltage relays; a metal bracket that supports the printed circuit board and the substrate at a lower side and operates as a heat sink radiating heat; and a band shaped rubber isolating member surrounding and elastically supporting the second high voltage relay. a printed circuit board including a printed wired circuit electrically connected to the second high voltage relay and providing a DC power supply path between the charger and the battery by having an input terminal connected to the charger and an output terminal connected to the battery; a substrate installed at an upper position higher than the printed circuit board to support the first and second high voltage relays; a metal bracket that supports the printed circuit board and the substrate at a lower side and operates as a heat sink radiating heat; and a band shaped rubber isolating member surrounding and elastically supporting the second high voltage relay.