A blower with the improved P-Q characteristics is provided. A blower comprising a shaft rotatably supported in a tubular casing, a cup shaped motor yoke 11 fixed to the shaft, and a body portion 15 of an impeller 14 comprising a large number of blades 13 on an outer peripheral portion is fixed to the motor yoke 11, wherein the blower is characterized in that substantially ring-like openings 15b are provided at a portion where the blades 13 of the body portion 15 are mounted and on a circumference around the shaft. Since air flow is facilitated by the openings 15b, the P-Q (pressure--flow rate) characteristics are improved.