Abstract: A powder pump includes a stator having a through hole that comprised of two spirally extended grooves, and a rotor, which is rotatably provided to the through hole of the stator and is spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator. The rotor is configured to convey the powder enclosed in the cavity while moving the cavity. Wherein the expressions ((RA−SN)≧0.45 and ((RB−(SN+SX)/2)≧0.45), one satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, a maximum inner diameter of the through hole, are in millimeters and represented by RA, RB, SN, and SX, respectively.