A vector control type electric power steering apparatus that compensates a dead time of an inverter, a motor back-EMF and an interference voltage by means of a mutual inductance between motor windings, improves a distortion of a current waveform and a responsibility of a current control, and suppresses a noisy sound, vibration and a ripple. The apparatus driving-controls a three-phase brushless motor which applies an assist torque to a steering mechanism of a vehicle by using a current command value calculated based on at least a steering torque, and vector-controls the three-phase brushless motor by using dq-axis command values that are converted from the current command value via an inverter, including: a 3-phase disturbance observer to compensate respective phase disturbance voltages, which include a dead time of the inverter, for 3-phase voltage command values.