In a brushless motor for an electric power steering device having a configuration of 2 poles and 3 slots, or of an integral multiple thereof, a stator coil is supplied with current containing a higher harmonic component. A difference of 0.5% to 1.5% is provided between the higher harmonic component content rate of the stator coil current and the higher harmonic component content rate of the induced electromotive force generated in the stator coil with rotation of a permanent magnet, thereby mitigating the influence by an armature reaction generated in the induced electromotive force to reduce torque ripples. The difference between the higher harmonic component content rates is set on the basis of a change that occurs in the induced electromotive force due to the armature reaction at a time of supplying electricity to the armature coil.