PURPOSE: To reduce the air resistance and noises without giving rise to turbulence by providing a motor stay with a reinforcing ring of circular cross-section adjacent to the air delivery section and delivering air along the arcuate face of the ring.

CONSTITUTION: A propeller fan 3 is driven by a motor 4, and it makes the air flow out of an air delivery section 5 provided on a base plate 1 which becomes an outer box. A motor stay 6 is provided on the base plate 1 in order to support fixedly the motor 4, and a reinforcement ring 7 which has a circular cross-section and is provided for strengthening is installed adjacent to the outer circumference of an air delivery section 5. The air flow y which flows out by the rotation of a propeller fan 3 is discharged smoothly without developing air turbulence by means of the reinforcement ring 7, and the air resistance can be thereby reduced, reducing noises and improving fan efficiency. Furthermore, a higher fan efficiency can be obtained by giving the reinforcement ring a shape which follows the air flow y.