Abstract: The portable abrasive tool comprises a flat motor composed of a rotor having a coil disk in the form of a disk on which multiple coil pieces are arranged in the circumferential direction about the output shaft when seen in the direction of the axis line of the output shaft and a stator having magnets arranged in the manner that the magnetic flux passes through the coil disk in the direction of the axis line of the output shaft, and an abrasive part connected to one end of the output shaft of the flat motor.