PURPOSE: To make the air flow in a duct uniform and let the air blow in a preferred direction.

CONSTITUTION: A blast direction changing wall 13 is provided that runs substantially along the center line 12 in a side ventilator duct 5 from the bending section of a side ventilator duct 5 to near a side blow-out port 2. And the side section 14 on the upstream side of the blast direction changing wall 13 is positioned to the outside from the center line 12 and the side section 15 on the downstream side is directed to the inside of the center line 12. With this arrangement the air flow is not deflected but uniform. Accordingly the air blows out also from the right half of the side blow-out port 2 on the left side, for example, and it is possible to blow the air out in a preferred direction.