To provide a motor drive adapted to operate stably and suffer essentially no damage, even when a high voltage is applied between grounding terminals of upper and lower arms.The motor drive of this invention includes: an arm with a first electric power semiconductor-switching element and a second electric power semiconductor-switching element, both connected in series between major terminals; and a level-shifting circuit that transmits a control signal of the first semiconductor-switching element connected to the high-voltage side of the arm, from a low-voltage circuit to a high-voltage circuit; the motor drive employing an insulated-gate bipolar transistor as the signal-transmitting high-withstand-voltage element formed in the level-shifting circuit.