A method of controlling a washing machine comprising a drum rotated by a drum motor, first and second balancing units (300a, 300b) to move along a circumference of the drum with laundry loaded therein, and a transmission coil provided at a tub containing wash water to generate a magnetic field and transmit power wirelessly to the first and second balancing units (300a, 300b), the method being characterized by the steps: sensing the magnetic field formed by the transmission coil, and receiving a position signal generated by a position sensing unit to sense a magnetic field formed by the transmission coil when the first balancing unit passes through the transmission coil; counting a pulse signal for each set unit angle generated by a hall sensor detecting a rotation angle of the drum motor; receiving the position signal generated by the position sensing unit to sense the magnetic field formed by the transmission coil, when the second balancing unit pass through the transmission coil; and calculating an angle between the first balancing unit and the second balancing unit from counting a number of pulse signals and the unit angle which are received after receipt of the position signal of the first balancing unit and before receipt of the position signal of the second balancing unit. a drum rotated by a drum motor, first and second balancing units (300a, 300b) to move along a circumference of the drum with laundry loaded therein, and a transmission coil provided at a tub containing wash water to generate a magnetic field and transmit power wirelessly to the first and second balancing units (300a, 300b), the method being characterized by the steps: sensing the magnetic field formed by the transmission coil, and receiving a position signal generated by a position sensing unit to sense a magnetic field formed by the transmission coil when the first balancing unit passes through the transmission coil; counting a pulse signal for each set unit angle generated by a hall sensor detecting a rotation angle of the drum motor; receiving the position signal generated by the position sensing unit to sense the magnetic field formed by the transmission coil, when the second balancing unit pass through the transmission coil; and calculating an angle between the first balancing unit and the second balancing unit from counting a number of pulse signals and the unit angle which are received after receipt of the position signal of the first balancing unit and before receipt of the position signal of the second balancing unit. sensing the magnetic field formed by the transmission coil, and receiving a position signal generated by a position sensing unit to sense a magnetic field formed by the transmission coil when the first balancing unit passes through the transmission coil; counting a pulse signal for each set unit angle generated by a hall sensor detecting a rotation angle of the drum motor; receiving the position signal generated by the position sensing unit to sense the magnetic field formed by the transmission coil, when the second balancing unit pass through the transmission coil; and calculating an angle between the first balancing unit and the second balancing unit from counting a number of pulse signals and the unit angle which are received after receipt of the position signal of the first balancing unit and before receipt of the position signal of the second balancing unit.