PURPOSE: To prevent the air volume from being reduced and suppress the generation of noise by providing a guide member on the lower surface of a fan casing which has an air inlet on the lower surface.

CONSTITUTION: When the air in a room is sucked in from a vent hole 16 of a decorative frame 15 by a fan 25, the air flows on the inner surface 29 of a guide member 26 along an uneven part 30, and is guided to a communicating port 27, and sucked into a fan casing 17 from an air inlet 18 of the fan casing 17, and then, is discharged to the outside. At this time, the air which flows on the inner surface 29 of the guide member 26 is rectified by the uneven part 30, and flows from the vent hole 16 to the air inlet 18 smoothly. Therefore, the air can be prevented from colliding around the periphery of the air inlet 18 of the fan casing 17. For this reason, a pressure loss between the decorative frame 15 and fan casing 17 can be prevented and the air volume can be prevented from being reduced.