PURPOSE: To provide a DC brushless motor having no sensor for correcting the phase relation of rotating field between rotor and stator windings optimally during normal operation.

CONSTITUTION: A frequency generator 101 detects r.p.m. of a rotor 116 whereas a direction detecting means 103 detects rotational direction from a frequency signal. A counting means 106 performs counting operation depending on a direction detection signal and a frequency signal. Count value is then converted through a waveform generating means 109 into a waveform signal for inducing a corresponding rotating field in stator windings 703(703a-703c) thus rotary driving the rotor 116. When the content of the counting means 106 is corrected depending on the phase difference between current and terminal voltage of the stator winding 703, a highly efficient DC sensorless brushless motor in which torque ripple is suppressed can be realized.