A brushless electric motor driven by an inverter, comprising: a stator including a stator iron core having a stator winding, wherein the stator winding of the stator iron core is molded and formed integrally by an insulating resin and the stator wiring is driven by an inverter of pulse width modulation system; a rotor including a rotary member holding a plurality of permanent magnets in a peripheral direction opposite to the stator and one shaft, wherein the rotary member is attached to the shaft so that the shaft penetrates through the center of the rotary member; a pair of bearings having a plurality of iron balls, an outer ring and an inner ring for supporting the shaft; and a conductive bracket for fixing one bearing of the pair of bearings, wherein the outer ring of the one bearing is electrically connected to the bracket and the bracket is insulated from the stator iron core; characterized in that: the outer ring of the one bearing is insulated from the stator iron core by the insulating resin and the outer ring of the other bearing is fixed to the insulating resin; the electric motor further comprising an impedance adjusting member for adjusting the electrical impedance at the high frequency signal due to the pulse width modulation between the stator winding and the outer ring of the one bearing; the impedance adjusting member includes a capacitive or a resistive member; and the impedance adjusting member is interposed as electrically connected between the stator iron core and the bracket and matches the electrical impedance between the stator iron core and the inner ring of the one bearing with the electrical impedance between the stator iron core and the outer ring of the same one bearing. a stator including a stator iron core having a stator winding, wherein the stator winding of the stator iron core is molded and formed integrally by an insulating resin and the stator wiring is driven by an inverter of pulse width modulation system; a rotor including a rotary member holding a plurality of permanent magnets in a peripheral direction opposite to the stator and one shaft, wherein the rotary member is attached to the shaft so that the shaft penetrates through the center of the rotary member; a pair of bearings having a plurality of iron balls, an outer ring and an inner ring for supporting the shaft; and a conductive bracket for fixing one bearing of the pair of bearings, wherein the outer ring of the one bearing is electrically connected to the bracket and the bracket is insulated from the stator iron core; characterized in that: the outer ring of the one bearing is insulated from the stator iron core by the insulating resin and the outer ring of the other bearing is fixed to the insulating resin; the electric motor further comprising an impedance adjusting member for adjusting the electrical impedance at the high frequency signal due to the pulse width modulation between the stator winding and the outer ring of the one bearing; the impedance adjusting member includes a capacitive or a resistive member; and the impedance adjusting member is interposed as electrically connected between the stator iron core and the bracket and matches the electrical impedance between the stator iron core and the inner ring of the one bearing with the electrical impedance between the stator iron core and the outer ring of the same one bearing. the outer ring of the one bearing is insulated from the stator iron core by the insulating resin and the outer ring of the other bearing is fixed to the insulating resin; the electric motor further comprising an impedance adjusting member for adjusting the electrical impedance at the high frequency signal due to the pulse width modulation between the stator winding and the outer ring of the one bearing; the impedance adjusting member includes a capacitive or a resistive member; and the impedance adjusting member is interposed as electrically connected between the stator iron core and the bracket and matches the electrical impedance between the stator iron core and the inner ring of the one bearing with the electrical impedance between the stator iron core and the outer ring of the same one bearing.