A dust collector comprises a tank having an intake opening; a head unit mounted on the tank; a motor provided on the head unit and having a rotor, a stator and an output shaft; a fan provided on the head unit and rotating under power from the motor, for sucking air or liquids into the tank from the intake opening; and a filter housed in the tank, that separates dust from the air or liquid sucked into the tank. The rotor has a coil disc having multiple roughly annular coils arranged in a circumferential direction centered on the output shaft in the direction of the axial line of the output shaft. The stator has a magnetic flux generation mechanism that generates magnetic flux that passes through the coil disc in the direction of the axial line of the output shaft.