Disclosed are a device and a method for stably stopping a motor. In this method, a first d-axis current reference value (id_ref1), a first q-axis current reference value (iq_ref1), and a first synchronous angle (Theta_fed) before a motor are stopped are set to be the initial values of a second d-axis current reference value (id_ref2), a second q-axis current reference value (iq_ref2) and a second synchronous angle (Theta_ref) for stopping the motor when stopping the motor. Moreover, when a normal control mode is changed to a stop braking mode, the d and q axes respectively use the same proportional integral controllers (4, 5), so that a severe current change and voltage change during the motor stopping are prevented, thereby smoothly stopping the motor without the occurrence of a pulsation or a reverse rotation of the motor before stopping.