A rotational angle sensor used in an electric power steering apparatus detects a rotational angle of a motor shaft at a portion on a steering system side, as a motor rotational angle (θm). A MPU sets a base correction amount (Δθ′m) based on a q-axis actual current value (Iq). The MPU sets a rotational angle correction amount (Δθm) used to correct the motor rotational angle (θm) by decreasing the base correction amount (Δθ′m) as a rotational angular speed (ω) increases and by increasing the base correction amount (Δθ′m) as a torque differential value (dT/dt) increases.